"Attachment (with respect to Martin Schoeller)" by Nathaniel Gold

My son will be three-years-old next month and is still breastfeeding. In other words, he is a typical primate. However, when I tell most people about this the reactions I receive run the gamut from mild confusion to serious discomfort. Their concerns are usually that extended breastfeeding could be stunting his independence and emotional development–the “Linus Blanket Syndrome” in the words of Michael Zollicoffer, a pediatrician at the Herman & Walter Samuelson Children’s Hospital at Sinai Hospital in Baltimore. Worse yet, they hint that it might even cause “destructive” psychosexual problems that he will be burdened with throughout his adult life. Could they be right? Was our choice “a prescription for psychological disaster” as Fox News psychiatrist Keith Ablow wrote in response to TIME magazine’s provocative cover article on attachment parenting? Just when is the natural age to stop breastfeeding?

One thing I’ve learned in my research on human evolution is that people are quick to assume that what they do is “natural” simply because they don’t know of other examples where things are done differently. The primate brain is a pattern recognition machine and is adapted to quickly identify regularities in our environment. But when we are presented with the same pattern over and over again it is easy to fall victim to what is known as confirmation bias, or coming to false conclusions because the evidence we use does not come from a broad enough sample. In order to avoid falling for this bias on the question of extended breastfeeding the best way forward would be to draw from the largest sample possible: the entire primate lineage.

In their classic paper, “Life History Variation in Primates” published in the premier scientific journal Evolution, the British zoologists Paul H. Harvey at Oxford and Tim Clutton-Brock at Cambridge published the most comprehensive data then available on the world’s primates. The variables they measured included everything from litter size and age at weaning to adult female body weight and length of the estrous cycle among 135 primate species (including humans). By analyzing the relationships between these variables, using a statistical approach known as a regression analysis, they identified striking patterns that held across primate taxa.

One especially strong correlation was that adult female body weight was closely tied to their offspring’s weaning age, so much so that knowing the first would allow you to predict the second with a 91% success rate. As a result, as anthropologist Katherine A. Dettwyler has shown in her book Breastfeeding: Biocultural Perspectives (co-edited with Patricia Stuart-Macadam), it can be calculated that a young primate’s weaning age in days is equal to 2.71 times their mother’s body weight in grams to the 0.56 power. This calculation predicts, given the range of female body sizes around the world from the !Kung-San of South Africa to the Arctic Inuit, that humans should have an average weaning age of between 2.8 and 3.7 years old.

How well does this prediction hold for our species? According to data compiled by UNICEF, half of the world’s population continues breastfeeding until at least the age of two. Furthermore, weaning in these cases doesn’t mean the total cessation of breastfeeding. It simply means the introduction of solid foods, with supplemental breastfeeding continuing for months or even years. However, these statistics are all drawn from sedentary, agricultural societies that have at least some contact with modern trends in child development. What about those societies whose way of life is most like that of our Pleistocene ancestors?

To answer this question Yale University anthropologist Clellan Stearns Ford utilized the largest historical collection of anthropological data available, the Human Relations Area Files, and analyzed the weaning age of 64 non-Western “traditional” societies–small-scale horticultural and hunter-gatherer populations. His analysis (see Figure 1 below) determined that the average age of weaning is approximately three years old, just as Harvey and Clutton-Brock’s data predicted. Furthermore, because these traditional societies are dispersed throughout the globe and have no contact with one another (or often anyone except the visiting anthropologists) these societies offer a broad enough sample size to avoid the problem of confirmation bias.

Figure 1. A comparison of age at weaning in the United States and in 64 traditional societies. Reproduced from Stuart-Macadam & Dettwyler (1995).

“Regardless of ecology,” write anthropologist Barry Hewlett and psychologist Michael Lamb in their book Hunter-gatherer Childhoods, “hunting and gathering groups are characterized by frequent and extended breastfeeding and extraordinarily high levels of parent-child physical contact and proximity.”

In contrast to these global trends among traditional societies and non-Western countries, U.S. government data estimates that fewer than 15% of Americans continue nursing their infants after they are just six months old (while Canadians are slightly higher with an average of about 25%). Likewise, as detailed by the Organisation for Economic Co-operation and Development Family Database [PDF], most countries in Western Europe cluster in the same 15-25% range as those in North America.

The worldwide trends therefore seem to be relatively straightforward: most humans tend to wean at a similar stage in their life history as other primates, which works out to about three years old based on our relatively large body size. This weaning age can then be adjusted based on the environment or traditions in a particular culture. However, Western nations appear to be an outlier to what is otherwise a natural behavior for our species. On this point the World Health Organization and UNICEF are in line with the predictions from primate life history. Both global health organizations recommend the following:

Initiation of breastfeeding within the first hour after the birth; exclusive breastfeeding for the first six months; and continued breastfeeding for two years or more, together with safe, nutritionally adequate, age appropriate, responsive complementary feeding starting in the sixth month.

The benefits of extended breastfeeding have been demonstrated both in the less developed and the industrialized world. For example, research carried out in Burkina Faso by epidemiologist Simon Cousins for the Bulletin of the World Health Organization and in Washington, DC by Dr. Kathleen M. Buckley for the Journal of Human Lactation, both showed that extended breastfeeding until three years old resulted in lower rates of malnutrition compared to those who were not breastfed as long.

Longer duration of breastfeeding has also been shown to significantly improve a child’s immune response to infectious disease. Writing in the British Medical Journal, Kåre Mølbak and colleagues at the University of Copenhagen analyzed the incidence of diarrhea in weaned and partially breastfed children in the West African Republic of Guinea-Bissau. They determined that not only did breastfed children get sick less often than weaned children, but those who continued partial breastfeeding up until the age of three had the lowest rate of infection. As the authors concluded:

Apart from the remarkably higher incidence of diarrhea in weaned children the clear decline in the rates of diarrhea in breast fed children in the second year of life was also surprising since the older children were breast fed irregularly and their main diet was as for adults.

Identical results were found in rural East Bhutan by Erik Bøhler and colleagues from the Department of International Health in Oslo, Norway, as reported in the journal Acta Paediatrica.

“Breastfeeding between 12 and 36 months of age was associated with reduced risk of diarrhea,” wrote the authors. “Breastfed children also gained significantly more weight during the monsoon season, and breastfeeding protected children against weight loss due to diarrhea.”

The unusually low level of breastfeeding in the United States therefore has public health implications rather than simply being a lifestyle choice. Ultimately, mothers–as well as fathers–need to decide for themselves how much, or how little, breastfeeding they are comfortable with. However, as a society, we can support their choices by making sure that everyone has access to reliable information and by creating a positive environment so that breastfeeding mothers aren’t subject to social stigmas or value judgements for doing what, after all, is only natural.

This piece has been corrected from how it originally appeared. Katherine A. Dettwyler calculated that human weaning should occur between 2.8 to 3.7 years old, not Harvey and Clutton-Brock.

          "Sarah Blaffer Hrdy" by Nathaniel Gold

As I explored in my article, “Women and Children First”, Sarah Blaffer Hrdy has faced innumerable challenges in the course of her scientific career. However, part of what makes her work so innovative and exciting to read is how she’s used those challenges to gain a deeper perspective into the process of evolutionary change. While it used to be universally assumed (and in some circles it still is) that males in many species will often seek out multiple sexual partners, the evolutionary logic for females was moored in Victorian ideas of female chastity. Ironically, all it took was for biologists to pay attention and document what the female of the species was actually up to in order to undermine a century of scientific assumption. Hrdy’s work, beginning with The Woman That Never Evolved, was central to a change in perspective that has occurred during the last thirty years.

The recent approach her work has taken with Mothers and Others: The Evolutionary Origins of Mutual Understanding offers nothing less than a reorientation of what it means to be human. If, as Hrdy proposes, we are a species that has thrived as a result of cooperative breeding–a childrearing strategy in which a network of individuals helps to raise a healthy child–it challenges many of the individualist assumptions that Western society is based on, particularly in the United States. How we can shift our society to reemphasize community will be the project that this generation will grapple with. Fortunately, there are scholars like Hrdy to offer their insight so that we won’t feel all alone while we do.

Hrdy with her newborn daughter, Katrinka. Image courtesy of Sarah Hrdy.

Eric Michael Johnson: You made a difficult decision, just before you got your offer to write Mother Nature, to choose a different life-work balance than the standard tenure track career. How was your work in primatology influencing your decisions as you were thinking about family life and having children?

Sarah Blaffer Hrdy: In 1986 I actually submitted a proposal to the Guggenheim foundation to write a book on the natural history of mothering. So I was already thinking about it. I was 41 and that was also the year that my third child, Niko, was born and, I’m sure this won’t surprise you Eric, but the book on the natural history of motherhood did not get written that year. I wrote a paper on delegating maternal care, the wet nursing paper, but I didn’t even come close to getting a book written. I had three children and then my brother and mother died within a year of each other. As my mother was dying I was very torn between the needs of my children and my job back in California. I was very close to her and she needed me in Texas. I began to suffer all of these psychosomatic illnesses such as back and neck pain, migraines. It was not working for me. Plus I had always wanted to be a writer, like you I think.

Johnson: Yes.

Hrdy: The balance of my life did not feel right. Furthermore, the state of my field was such that teaching in an anthropology department was not bringing me a whole lot of satisfaction. It’s so hard to talk about it and tell the truth because there were so many different angles to it. But, basically, I wrote a book proposal, submitted it to publishers, there was an auction, the book was sold, and I immediately resigned from the university. I was offered to take the status of Professor Emerita, which I thought was an attractive offer. It didn’t come with any pension or medical benefits but, because my work had been so controversial, it was a way for me to quit with dignity. So that’s what I did. That was 1996 and the next three years I didn’t do anything except write and attend to my family (and, as you know, just because they’re not babies anymore doesn’t mean they don’t need a lot of attention).

Johnson: I know that all too well. You were mentioning earlier the importance of attachment in child development. How do you see that playing out today?

Hrdy: Remember that terrible case of Andrea Yates, the mother who was left on her own when she was already suffering from postpartum depression? She may have even been suffering from worse mental conditions that that. I think she had five children under the age of 8. One day she completely loses it and kills her kids and in Texas she’s sent to prison. The focus was on how awful this was, and, of course it was awful. But there was no deeper questioning. What was this mother–already identified as suffering psychological duress–doing alone with five children without social or institutional support of any kind? We have forgotten to put events like these murders into a larger perspective.

Hrdy on the cover of the Boston Globe Sunday magazine.

I think it’s starting to come back in sociologically informed circles to recognize just how much social support mothers in our species need. But it’s certainly not generally recognized at the level, for example, of politicians who are still out there talking about how they know children are healthier when they’re reared with a mother who is married to their father. We have these powerful social prescriptions about this with really no data to back it up. To say that a married mother with children is actually better off than a single mother with just one person taking care of the kids, well duh, that’s obvious. But we don’t know, for example, that those children are better off than they would be if they were in a family with a mother and a father and a grandmother and nieces and nephews in the family, or if they were better off with a grandmother, an aunt, and a mother. We really don’t know because those aren’t the kinds of studies we’ve done. The studies have all looked at married versus unmarried or nuclear family versus single mother.

We need to do much more before we can make these kinds of claims. Judges are making decisions about whether or not children can be in a particular school or who can have custody of children depending on this assumption that children are better off in certain kinds of family configurations. But there is so little science actually informing these pronouncements. Historians of the family and many social workers have felt for a long time that children actually do better in extended families. So I’m rather pleased to notice, as we are coming out of this terrible recession and collapse of the housing market, that one of the few bright areas in the housing market are the multifamily houses or apartments being built. There are actually special rooms so that in-laws or grandparents can live with nuclear families. I think part of the reason for this is, of course, financial since people are struggling to pay their rent or mortgage. But I also think there’s a recognition that these extra people are playing a very important role in providing the kind of nurturing environment that our children need. I’m glad to see that.

Johnson: Are there other societies that have also recognized this?

Hrdy: Actually, yes. For example, in countries like Mexico they still have very intact traditions of extended family. However, like us, and for the same reasons, they are moving away from that. It’s really too bad. But our economic environment is set up for people to move where they can get jobs and our housing configurations aren’t designed for living with kin or in close contact with other family members. We seem to have a greater concern with privacy and owning individual homes surrounded by their own yards. They’re really not conducive to what children need.

Johnson: What happens?

Hrdy: Well, for one thing, a lot of child abuse and neglect. It’s probably increasing, but when I say increasing you have to pay attention to what I take as my starting point. If you’re starting from medieval times, I think children are being treated much better today. We don’t swaddle babies and hang them from a door while mothers and other family members go out to the fields to work, hang them up so they won’t fall in the fire or get eaten by pigs. Thankfully we don’t see the level of neglect like there was in, for example, 18th century France that I describe in Mother Nature, where babies are being sent off to wet nurses in the country then (if against the odds they survived) wrenched away and returned to a mother they barely knew. Compared to earlier phases in Western civilization children are better off today. But not compared to our Pleistocene ancestors. Child survival rates are exponentially higher today. That’s true. But those children who did survive back then were actually much better off in terms of the kind of nurturing environment that they experienced. Rates of child mortality were high, but there was no child abuse or emotional neglect. A child that has experienced the kind of emotional neglect it takes to produce the psychopathology of insecure attachment, the kind shown in Bowlby and Harlow’s work, simply would not have survived. Parents and other group members are very sensitive to anything that would threaten a child’s survival.

If you look at the ethnographic accounts of band-level hunter-gatherer in Africa or Melanesia—though I’m not sure I can say this for South America—what jumps out at you is the indulgence towards children. Child abuse would not have been tolerated. Other group members would have intervened, the perpetrators socially ostracized, possibly even expelled from the group if they harmed a child. It was not acceptable. We don’t have this same sensibility today for a number of reasons. I think we have an epidemic of emotional neglect of children today that has gone completely unrecognised.

Johnson: Why do you think cooperative breeding disappeared as a parenting strategy?

Hrdy: I think what disappeared was the flexibility in residence for women. I think as hunter-gatherer groups became larger and more complex people had to begin defending the more compressed territories where they made their living. This was certainly the case with the Neolithic revolution and the invention of agriculture. Over time, as populations built up, as property became much more important—and it also became important to defend property—that’s when boundaries became less porous and men stayed together. To defend fixed areas it made sense to remain near brothers and fathers. Male kin alliances became much more important. Then I think two things happened: Women were moving between groups to places where they didn’t have matrilineal relatives and men were staying put, which changes the balance of power in all sorts of family relationships. But you also had group boundaries that were no longer as porous as they had been. This meant that a woman couldn’t simply take her children and leave to be near her kin if she wasn’t being well treated. I think that was the first big transition, women lost their autonomy over their own childrearing assets. And, of course, with patrilocality and the influence of patrilineal descent, you begin to have a concern with female chastity so that it really matters if a woman “goes off alone.” Not only are women losing but children are taking it on the chin.

Johnson: In what ways did this play out? What was the effect on women and children?

Hrdy: Consider the customs in very patriarchal societies, like the practice of suttee in parts of India, where after her husband dies a widow is expected to throw herself on the funeral pyre and burn herself alive. This protects patrilineal interests since the widow can’t remarry and confuse family lines or property claims, or dishonor the patriline by inappropriate sexual conduct. But this is only one way to look at it. If you look at it from the point of view of children you see how they are being deprived of these critically important allomothers, their great-aunts and grandmothers and sometimes even their mothers. That’s just one example; of course there are many others. We know from Donna Leonetti’s wonderful work comparing geographically proximate groups in Bengal and Asaam, both matrilineal and patrilineal societies, that they put very different priorities on child well-being. In societies where women have more say and purchase, women tend to be better off. While patriarchal ideologies promote fertility, they undermine child well-being. In recent history this has become tied to other traditions of the woman being responsible for everything that happens to her children. If anything goes wrong, blame the mother. We need to rethink that. If we evolved as cooperative breeders, when things go wrong we need to say that a larger community is at fault than just the mother.

Johnson: How did your research in primates influence your own parenting choices?

Hrdy: As a primatologist I was familiar with chimpanzee mothers who carried their babies everywhere. I was preadapted to be impressed by attachment theory. To me John Bowlby has made the greatest contributions to human well-being of any other evolutionary researcher with his recognition and validation of the needs of human infants to feel secure. Thus when Katrinka was born in 1977 I felt like any good Great Ape (read chimpanzee!) mother. I needed to be in continuous contact with my baby and respond immediately to her if she cried or signaled some need, ensuring that she would feel secure. I was absolutely convinced that this would produce a more confident and independent child, saving us a lot of grief later on. This was in stark contrast to how I was raised. Educated women in my mother’s generation thought that if you responded to a crying baby you would be conditioning that baby to cry more and to be more demanding. Of course, today we know the opposite to be the case. The more secure the baby is, the more freedom they’re willing to allow those around them. You want to respond to a baby right away and I understood this. Bowlby was very influenced by primatology and I was influenced by Bowlby, so essentially this kindly Victorian evolutionist was right in there in the nursery with me.

Hrdy's former teacher, Robert Trivers, providing alloparental support with Katrinka. Image courtesy of Sarah Hrdy.

I adored my baby. Yet as a woman turning my life over to this little gene vehicle, I was surprised by how I ambivalent I felt. I have always felt that my gestations were the average length and my sexual responses seemed to be average, so I had no reason to think that my reactions to motherhood were abnormal. I just figured I needed to understand maternal ambivalence a lot better than I did and I made that a research priority. The resulting book Mother Nature is really about maternal love and ambivalence. Human maternal ambivalence I came to realize is completely natural. If, instead of evolving like chimpanzees where mothers are turning themselves over in a totally dedicated, single-minded way to their infants, we had evolved as cooperative breeders, it makes sense that I would feel the need for more social support and more help rearing these children than an American woman living in Cambridge in the 1970s was likely to get as a postdoc. This made me rethink how maternal emotions and infant needs are playing out in our own species. By the time my third child was born, I felt I had my ducks in a row. I understood what my children needed much more and I also understood what their mother needed. I needed others around to help me provide the emotional security that these children required.

Johnson: When you reflect back on the series of nannies that raised you, how do you feel about that given everything you know now?

Hrdy: Actually I’m very interested in finding out more. I just wrote to my father’s youngest sister to ask her who cared for me when I was an infant because I don’t know and no one else is alive who really knows. I don’t have childhood memories and I have a very revered colleague, Mary Main at Berkeley who actually does research on adult attachment interviews and how the way we remember our own rearing experience effects the way we parent. These turn out to be quite powerfully predictive. It’s a very controversial area but I am convinced that even though some of the things they talk about are hard to measure, that they are extremely important.

I want to know so much more about my early childhood and I simply don’t. I have a feeling that others of my generation and social class are very much in the same boat. When my brother died at the age of 30, my younger sister gave me his baby book. I was amazed by how much detailed information there was in it. I had a sense that I knew who had been caring for him and it wasn’t the kind of people who’d be keeping a baby book. But then I looked more closely and I realized that it was my handwriting. I was keeping all these detailed notes on my brother’s development, but I have no recollection of caring for him. I find people without childhood memories really fascinating and I’m among them.

Johnson: I don’t understand. Why don’t people have childhood memories? Is it the attachment issue perhaps?

Hrdy: I guess. Forgive me, but what’s your earliest memory?

Johnson: My earliest memory is when I am two years old, roughly, and I’m looking into a mirror at myself.

Hrdy: Wow, that’s metaphorical. That’s wonderful Eric. Were you trying to decide if you had theory of mind. [Laughs]

Johnson: I just remember finding it fascinating.

Hrdy: I find your childhood memory really fascinating. Two years old is beyond my comprehension.

Johnson: I also remember sitting in my fathers lap, right around two years old, watching the movie Star Wars. It was the first movie my parents ever took me to.

Hrdy: Oh my gosh, Katrinka went to Star Wars. That was probably the first movie she ever went to, I’ll have to ask her if she remembers it. Well, that’s amazing. Thank you.

Johnson: Thank you so much for talking with me. I really enjoyed hearing your perspective and what made you into the researcher and the person you are today. It was a great pleasure.

Hrdy: I might turn the table some day, though I’ll check with you first. Two years old, looking into a mirror. Who am I? Where did I come from? That’s good. I hope you include that in your blog someday so I can cite it. I love it.

Johnson: Okay, sure. I will.

          "Sarah Blaffer Hrdy" by Nathaniel Gold

In my cover article out this week in Times Higher Education I featured the life and work of famed primatologist and evolutionary theorist Sarah Blaffer Hrdy. While she never intended to be a radical, she has nevertheless had a radical influence on how primatology and evolutionary biology address female strategies as well as the evolutionary influences on infants. Hrdy graduated summa cum laude from Radcliffe College in Cambridge, Massachusetts and received her Ph.D. in anthropology from Harvard. She is a former Guggenheim fellow and a member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the California Academy of Sciences. She is currently professor emeritus at the University of California, Davis.

In our discussion, Hrdy explores both her own life as well as how her personal experiences inspired her to ask different questions than many of her scientific colleagues. While it may not seem like a particularly dramatic idea to emphasize the evolutionary selection pressures on mothers and their offspring, it is a telling insight into the unconscious (and at times fully conscious) sexism that has long been a part of the scientific process. Through her work, in books such as The Woman that Never Evolved, selected by the New York Times as one of its Notable Books of 1981, Mother Nature: A History of Mothers, Infants and Natural Selection, chosen by both Publisher’s Weekly and Library Journal as one of the “Best Books of 1999″ and, her latest, Mothers and Others: The Evolutionary Origins of Mutual Understanding, Hrdy has challenged, and transcended, many of the flawed assumptions that biologists have held dating back to the Victorian era. It is a body of work that continues to provoke and inspire a new generation of scientists and was highly influential in my own scientific work.

The scientist as allomother. Hrdy with Shanika, the daughter of her colleague Dr. Anula Jayasuriya. Image courtesy of Sarah Hrdy.

Eric Michael Johnson: Why do you think it’s important to look at mothers and infants from an evolutionary perspective?

Sarah Blaffer Hrdy: If we really want to raise Darwin’s consciousness we need to expand evolutionary perspectives to include the Darwinian selection pressures on mothers and on infants. So much of our human narrative is about selection pressures but, when you stop to think and parse the hypotheses, they’re really about selection pressures on males: hunting hypotheses or lethal intergroup conflict hypotheses to explain human brains. Well, does that mean that females don’t have brains?

Johnson: In an autobiographical sketch published in the book Leaders in Animal Behavior you wrote that: “It was no accident that I would later become interested in the evolutionary and historical origins of patrilocal marriage, male-biased inheritance, female sexuality and peoples’ obsessive concerns with controlling it.” When did you start becoming interested in these topics and what were some of the leading motivations you had at the time?

Hrdy: You have to take into account where I grew up and when. It was in south Texas. I was born in 1946 so I was growing up in the 50s. This was a very segregated and really quite patriarchal society. Growing up in Houston was a lot like growing up in South Africa. Also within my family males had a very special role. The good news, in a way, is that I was the third daughter born in a family eventually of five. It was a very wealthy family and I was sort of the heiress to spare. So they didn’t pay too much attention to what I was doing, though they certainly had very set ideas about who I should marry and what sort of life I should lead. But once I was out of sight off at school, I was pretty much out of mind which was good for me. So I went off to school when I was 16 and that really was the beginning I think of my intellectual development.

Johnson: This was during the midst of what Betty Friedan later called “the feminine mystique.” In what ways did you see this dissatisfaction at play in the women around you? How did you interpret this as a girl when looking to grownups for a model of womanhood?

Hrdy: Oh Eric, I was so clueless. I didn’t understand. I had no political awareness at all. I was really finding it out for myself. I still recall sitting in a simian seminar at Harvard and the discussion revolved around women being exchanged between groups as a way of connecting male brotherhoods and achieving alliances between groups. I remember thinking to myself, “This is what it must be like to be a black person listening to a lecture in support of the Ku Klux Klan.” I had no sense of the culture I’d grown up in and the way women were regarded within it. I had no sense of what this was really about and how it was working. I was learning from politically more aware people around me who, I think, often were stunned at my naiveté. At that time primate behavior and the whole evolutionary endeavor was steeped in these very Victorian preconceptions. So I was reacting, at a very visceral level, even before I realized what was going on.

Johnson: And when you entered college?

Hrdy: The year I graduated [from Radcliffe in 1969] there was not a single woman professor at Harvard and I was my professor’s first woman graduate student. Female role models, especially in the sciences, were almost nonexistent. Moving closer to biology was a different thing for me than being an undergraduate in cultural anthropology. The dominant narrative about primate social lives was the savannah baboon where males are very political and dominant and they would support each other so they could control females. Are you familiar with those stories?

Johnson: Of course, that was one of the dominant paradigms for human evolution at the time.

Hrdy: And it was. That’s what I was hearing and that’s what I was responding to. There was really no consideration of how much variation existed among females. Remember, the models back then held that there was variance in male’s reproductive success and no variance in female’s. It was assumed every female would be a mother and would breed to the maximum of her capacity so that females would be producing about the same number of offspring each whereas, with males, they could do tremendously well or be a complete zero — what was referred to as “the Bateman paradigm”. Supposedly, because the ovary was bigger and more resource rich than the sperm, it meant there were many tiny sperm actively competing for a large, resource rich ovum. This was the basis for the assumption that there was stronger selection pressure on males than on females.

A few of Hrdy's books: The Woman that Never Evolved, Mother Nature, and Mothers and Others.

Johnson: What led you to question this paradigm?

Hrdy: It was after I started studying langur monkeys that it began to dawn on me how many sources of variation in female reproductive success there were. It brought the old paradigm into question. For so long it had been assumed that males were basically polygynous [many sexual partners] while females were monandrous [one sexual partner]. Watching langurs convinced me that this was not true. When I examined the wider literature I realized just how common polyandrous mating by females actually was across primates. Now we realize it’s not just primates, it’s across the animal kingdom.

This was all starting to emerge at the time and it really gelled for me in a paper I prepared for the first (and really only) overtly feminist conference I ever attended organized by Ruth Bleier in 1985. Almost none of my colleagues from biology read that essay — “Empathy, Polyandry, and the Myth of the Coy Female” at the time, but it was recently republished in Elliot Sober’s Conceptual Issues in Evolutionary Biology [pp. 131-160]. The essay was about how inapplicable, or wrongly applied, the Bateman paradigm was. There was so much more selection on females to mate with multiple males for a variety of reasons, from genetic reasons to extracting more investment, or confusing the issue of paternity. By the 1970s, I recognized that paternity confusion was what was going on with langurs. But this was heresy back then. Now I think it’s widely accepted. I think the history and the feminist provenance of this idea has been forgotten which, in a way, is too bad because we know what happens when you forget history, old mistakes get repeated, old biases reinserted. I see no reason why some of these same biases couldn’t come back in other forms just as appears to be happening in our political sphere today.

Johnson: Earlier I interviewed you about patrilocal residence patterns and how that alters women’s sexual choices. In contrast, matrilocal societies are more likely to be egalitarian. What are the factors that lead to the differences between these two systems?

Hrdy: I think in societies where women have more say, and that does tend to be in societies that are matrilocal and with matrilineal descent or where, as it is among many small scale hunter-gatherers, you have porous social boundaries and flexible residence patterns. If I had to say what kind of residence patterns our ancestors had it would have been very flexible, what Frank Marlowe calls multilocal. This means they were sometimes matrilocal and living with a woman’s family, or sometimes patrilocal and living with a man’s family. Or sometimes they weren’t living with either family because they could vote with their feet and move away if someone was being oppressive. I think these porous boundaries and flexible residence patterns were very important for our ancestors. But, over time, as populations built up and property became much more important—and it also becomes important to defend property—that’s when it became much harder to move between groups. The boundaries became less porous but also men would tend to stay together. Sons would stay near where their brothers and fathers were because they made the best allies for defending a particular resource.

As I suspect you know, I am convinced that until fairly recently in human history–-and of course, for me, recent means 10-20,000 years ago–-people weren’t defending resources. The ranging areas were so large that is very difficult to imagine anyone defending them. There was also no property, so they weren’t defending that either. Some people have argued that they were defending women because men are always going to be looking for extra wives and extra women to mate with. But the thing is, among hunter-gatherers, the way to breed successfully is having alloparental help and provisioning help from others. Anybody who goes around killing off his wife’s relatives and stealing women is going to have a lower chance of rearing offspring. These warring bands of brothers didn’t emerge until fairly recently, after people started to become more sedentary. For these reasons, I think our hunter-gatherer ancestors had a flexible residence pattern and that group boundaries were porous.

Johnson: As you argue in your latest book, Mothers and Others, humans evolved as cooperative breeders. However, most psychology studies (and nearly all parenting advice books) assume that the nuclear family is integral to human nature. How does this assumption influence the kind of advice parents receive?

Hrdy with her newborn baby, Katrinka. Image courtesy of Sarah Hrdy.

Hrdy: By the time I was finishing Mother Nature I had realized that there was simply no way an ape with the life history traits observed in humans could have evolved unless our ancestors had been cooperative breeders. By this I mean a species where alloparents, individuals other than the parents, had helped to care for and also provision the youngsters. That’s the best explanation for the life history traits that you have in humans, these very long periods of dependency that anthropologists studying hunter-gatherers have documented. In other apes, once youngsters are weaned they’re basically nutritionally independent. But in humans offspring are going to be between 18-20 years old before they are producing as many calories as they’re consuming. So the dependency is lasting a very long time. Hillard Kaplan’s work has been very important to me. He estimates that it takes 13 million calories to rear a human from birth to nutritional independence and this is far more than a woman could provide by herself. Furthermore, the work of anthropologists like Kristen Hawkes and James O’Connell have shown that it would take more than both the mother and the father could have provided.

Johnson: So who was helping?

Hrdy: That’s where different emphases are being proposed and I take the view that it’s very opportunistic and mothers are getting help wherever they can. It can come from grandmothers, as Kristen Hawkes has stressed, and post-reproductive females. It can also come from fathers and males that might be the fathers, from patrilineal relatives, matrilineal relatives, older siblings, aunts, uncles, and even sometimes nonrelatives who happen to be in the group who are earning their keep by helping to rear the youngsters. It would be a varied assortment of helpers, albeit group members very familiar to the child.

Johnson: How could this human past help us today to design more compatible childrearing systems that are more geared to the needs of children?

Hrdy: What we learned from Bowlby, who’s been so important to me with attachment theory, is that children need this sense of security that comes from having close relationships from people around them. But where I depart from Bowlby is in assuming that the mother is the sole attachment figure. Of course, later, Bowlby did correct himself somewhat under the influence of Mary Ainsworth, so I want to give Bowlby credit for changing his views over the course of his career. But, for the most part, he was convinced that the mother was more than the primary caretaker, she was the one that mattered most. As a consequence, most studies of attachment theory focused on the infant’s relationship with the mother. Yet a handful of studies that actually looked, noted that children with multiple attachment figures are better able to integrate the perspectives of multiple people. Marinus von IJzendoorn and Avi Sagi-Schwartz’s work has been especially important to me in this regards. Perspective taking is one of the key differences between humans and some of our closest ape relatives. We don’t really know whether a child who has, for example, equal amounts of care from the mother and the grandmother or more caretaking from the father can’t be just as secure with that person as with the mother. However, I predict that they would.

Johnson: How does the assumption of the standard nuclear family affect the kinds of approaches that humans have towards parenting? If, as you say, we have evolved as cooperative breeders?

Hrdy: I don’t think it can be separated from patriarchal traditions. A woman living in a patrilocal setting is surrounded by her husband’s people. She’s a fairly isolated figure and her role is going to be, essentially, a breeding machine for the patriline. She won’t have social support within her husband’s community. Out of that long tradition there emerges this view of the mother as an all-giving, totally dedicated creature who turns herself over to her children. I went back and read some of the early stereotypical views of motherhood in Western Europe and all of them were conflated with notions of charity and a woman giving of herself as the model for what a woman should be. If you stop to think about this you realize that these are all from the perspective of the patriline and the male’s perspective. It’s really not taking into account the woman’s perspective.

Click here for Part Two: Sarah Blaffer Hrdy on the Evolutionary Lessons of Motherhood

            "Tantrum" by Nathaniel Gold

The infants had been arranged into neat rows, swaddled in aseptic white cloth the way precision instruments would be secured for shipping. Masked, hooded and gloved nurses cautiously moved down the aisle to record vital functions and administer bottles of formula, closely adhering to the feeding schedule detailed in their log books. To eliminate the possibility of contamination, any handling of their charges was kept to a minimum and parental visits were strictly forbidden. It was a model of efficiency compromised only by the piercing screams of newborns in distress.

American infant wards in the first half of the 20th century were designed around two prevailing ideas, wrote Robert Sapolsky, a Stanford University neuroscientist, in his book Monkeyluv: And Other Essays on Our Lives as Animals (2005): “a worship of sterile, aseptic conditions at all costs, and the belief among the (overwhelmingly male) paediatric establishment that touching, holding, and nurturing infants was sentimental maternal foolishness”.

The above is the opening from my new cover article in Times Higher Education out this week (see my last one here) that explores the science of childhood attachment. The piece brings together two overlapping narratives. One strand focuses on the work of primatologist and evolutionary theorist Sarah Blaffer Hrdy and chronicles her personal story of living with the legacy of insecure attachment. The other explores the science that she has spent her career documenting about the evolutionary influences on mothers and offspring, as well as how we can learn from natural history to better provide a secure environment for children today. In addition to Hrdy I interview the evolutionary biologist Robert Trivers, anthropologist Barry Hewlett, and science writer Deborah Blum to show how the science of mother and offspring behavior has challenged many of the assumptions that evolutionary theorists have held for generations.

However, for Hrdy, this research is more than just an academic exercise; it is highly personal as I detail in my article:

“No one ever doubted that my mother loved her five children,” Hrdy says, but as a result of her upbringing, “I was a case study in insecure attachment and, except with friends, quite shy.” Hrdy would eventually learn to overcome her shyness, but the absence of an emotional bond during her early development left behind a permanent scar: to this day she has no memory of childhood.

In 1990, after Hrdy’s brother died tragically at the age of 30, she received his baby book from their early childhood in Houston.

“I was amazed by how much detailed information there was in it,” she says. Having only vague impressions of their distant caregivers, Hrdy couldn’t imagine that one of them had kept such a complete record.

“But then I looked more closely and I realised that it was my handwriting,” she says. “I was keeping all of these detailed notes on my brother’s development, but I have no recollection of caring for him.”

The precise mechanism for such childhood memory loss continues to be debated by psychologists, but the common experiences of adults who share this kind of amnesia form a consistent pattern. Like those children who suffered the effects of hospitalism in the early part of the 20th century, the absence of childhood attachment with a caregiver results in physiological changes that have potentially lifelong consequences.

The early pioneers in the science of childhood attachment were the psychologists John Bowlby and Harry Harlow whose research laid the foundation for a field change among their colleagues. Up until the 1950s the school of thought known as behaviorism was all but universally accepted among psychologists. This school held that everything that animals do–including mental traits–should be understood as behaviors. By changing the behaviors it was thought you could change how individuals think or even feel. However, by putting these assumptions to the test they were demonstrated to be woefully inadequate, as I show through the experiments done on primate infants.

At the same time that Bowlby was developing his evolutionary theory of attachment in the mid-1950s, a hard-drinking, chain-smoking workaholic by the name of Harry Harlow was busy creating separation anxiety in the lab. While his original intention was to discover the cheapest way to breed monkeys for experimentation, Harlow ended up providing empirical evidence to refute those psychologists who advocated a cold, emotionless approach to parenting by creating the kind of wiry caregiver that they described, quite literally.

By placing a baby monkey into a cage with two artificial “surrogate” mothers – one made of soft terrycloth and the other a patchwork of wire mesh – Harlow sought to test the behaviourists’ assumption that an infant was motivated only by a parent who provided them with nourishment. In the course of the experiment, eight identical cages would be established, but with one important variation: in four of them, only the “wire mom” would be equipped with a bottle, while in the other half only the “cloth mom” would be. If the behaviourists were correct, the infant should prefer whichever “mother” was the source of food.

The results were unambiguous: in both cases infants spent nearly all of their time clinging to their cloth mother regardless of whether or not it was the one with the bottle. In the cages where wire mom was so equipped, the infants would leave soft mom’s embrace to feed, only to immediately return for the “contact comfort” they obviously required.

“The effects were so strong”, wrote Deborah Blum, the Pulitzer prizewinning journalist who chronicled Harlow’s experiment in her book Love at Goon Park: Harry Harlow and the Science of Affection (2002), “that the scientists began to wonder about other ways to test that bond and the security that seemed to come with it.”

Harlow next placed each infant – along with both surrogate mothers – into a 6 sq ft playspace that the monkeys could explore independently. When cloth mom was present, the infants would each hesitantly wander around their novel environment, confident that they could return to the safety of their surrogate’s embrace if they needed to. But in those trials where Harlow had cloth mom removed, the infants would huddle in the corner screeching, sucking their hands or rocking back and forth repeatedly. Even those infants who were used to feeding from wire mom had a similar response: she was no better than the strange objects that surrounded her.

Subsequent experiments, this time with flesh-and-blood mothers, found that only those infants who had first established a secure attachment could successfully forge relationships with other members of their group. Without this, infants would experience heightened anxiety in social situations, just as Bowlby described for children with insecure attachment.

It is from this foundation that the science of childhood attachment gets truly interesting and, as Hrdy and Trivers go on to explain, inverts the perspective that evolutionary biologists have held dating back to the Victorian era.

The uniting of behavioural and genomic evidence, something that Hrdy and Trivers have independently explored throughout their careers, has revolutionised the way that mothers and children are viewed from the perspective of natural history. And rather than an evolutionary logic that places men at the top of the hierarchy, followed by women and children at lower levels, the perspective has now been inverted.

“Instead of the classical, so-called ‘patriarchal’ society,” Trivers says, “the logic goes the other way around: children; women as primary investors; lastly and hardest to justify, males.”

Thanks for reading and I will do my best to answer any questions you may have in the comments below.

               "American Chimp" by Nathaniel Gold

Americans take their rights seriously. But there is a lot of misunderstanding about what actually constitutes a ‘right.’ Religious believers are correct that they have a right to freely express their beliefs. This right is protected under the First Amendment to the US Constitution that prohibits Congress from making any “law respecting an establishment of religion, or prohibiting the free exercise thereof.” However, as a result, devout believers feel it is a violation of their rights when intelligent design creationism is forbidden in the classroom or when prayer during school sporting events is banned. After all, shouldn’t the First Amendment prohibit the government from interfering with this basic right?

The answer is no and represents an important distinction when understanding what a right actually is. Because public schools are government-run institutions, allowing prayer during school activities or promoting religious doctrines in the classroom is a direct violation of the First Amendment. These activities infringe on the rights of those who do not share the same religious beliefs (or any at all). The key point is that rights are obligations that require governments to act in certain ways and refrain from acting in others. The First Amendment obligates the government to protect the rights of all citizens from an establishment of religion. You may have the right to freely exercise your beliefs, but that doesn’t give you the right to impose your views on others in public school.

It was just this understanding of rights as obligations that governments must obey that formed the basis for a declaration of rights for cetaceans (whales and dolphins) at the annual meeting of the American Association for the Advancement of Science held in Vancouver, Canada last month. Such a declaration is a minefield ripe for misunderstanding, as the BBC quickly demonstrated with their headline, “Dolphins deserve same rights as humans, say scientists.” However, according to Thomas I. White, Conrad N. Hilton Chair of Business Ethics at Loyola Marymount University in Los Angeles, the idea of granting personhood rights to nonhumans would not make them equal to humans. They would not vote, sit on a jury, or attend public school. However, by legally making whales and dolphins “nonhuman persons,” with individual rights under law, it would obligate governments to protect cetaceans from slaughter or abuse.

“The evidence for cognitive and affective sophistication—currently most strongly documented in dolphins—supports the claim that these cetaceans are ‘non-human persons,’” said White. As a result, cetaceans should be seen as “beyond use” by humans and have “moral standing” as individuals. “It is, therefore, ethically indefensible to kill, injure or keep these beings captive for human purposes,” he said.

This is not as radical an idea as it may sound. The law is fully capable of making and unmaking “persons” in the strictly legal sense. For example, one Supreme Court case in 1894 (Lockwood, Ex Parte 154 U.S. 116) decided that it was up to the states “to determine whether the word ‘person’ as therein used [in the statute] is confined to males, and whether women are admitted to practice law in that commonwealth.” As atrocious as this ruling sounds, such a precedent continued well into the twentieth century and, in 1931, a Massachusetts judge ruled that women could be denied eligibility to jury status because the word “person” was a term that could be interpreted by the court.

Such a flexible interpretation of personhood was demonstrated most dramatically in 1886 when the Supreme Court granted personhood status to the first nonhuman. In this case it was a corporation and Southern Pacific Railroad (part of robber baron Leland Stanford’s empire) snuck in through a legal loophole to gain full personhood rights under the 14th Amendment. Such rights have now been extended to all corporations under the Citizens United ruling in 2010, which is what allowed Mitt Romney to confidently declare “corporations are people, my friends.”

But prior to 1886, dating back to the 1600s, corporations were viewed as “artificial persons,” a legal turn of phrase that offered certain rights to the companies but without the full rights of citizens. By using the wording of the 14th Amendment (intended to protect former slaves from a state government seeking to “deprive any person of life, liberty, or property, without due process of law”) it was ruled that corporations should enjoy the same status. As a result, between 1890 and 1920, out of all the 14th Amendment cases that came before the Supreme Court, 19 dealt with African-Americans while 288 dealt with corporations. With the legal stroke of a pen, artificial persons were granted all the protections of citizens.

But that would be unlikely to happen with whales, dolphins, or even great apes. A “nonhuman person” would have a definition similar to this earlier tradition of “artificial person,” one that grants limited rights that a government is obligated to protect. Furthermore, according to White, the term would only apply under very specific criteria for nonhumans that had self-awareness, complex social as well as emotional lives, and evidence of conscious awareness (so, for example, ants would never be considered persons under law). According to White, these criteria have been met in the case of dolphins and whales and our legal institutions should incorporate this evidence into American jurisprudence.

“One of the most important aspects of science is that scientific progress regularly raises important ethical questions,” said White. “As scientific research produces a more accurate picture of the universe, it often reveals ways that human attitudes and behavior may be out of synch with these new facts.”

This has already been established in some parts of the world. In 2008 the Spanish Parliament came to a similar conclusion for great apes that would grant limited personhood rights to nonhuman animals for the first time so that, according to The Guardian newspaper, they “should enjoy the right to life, freedom and not to be tortured.” This ruling came one year after Austrian animal rights advocates had attempted, and failed, to adopt the chimpanzee Hiasl so that he couldn’t be sold to a zoo or laboratory. The judge in that case decided that chimpanzees were defined as property and therefore couldn’t be adopted (something that the law allows only for “persons”). However, as the history of this term suggests, there is nothing inherent to modern legal frameworks that would prevent a different judge from coming to another conclusion.

                  "@BoraChimp" by Nathaniel Gold

Conferences are social grooming events for relatively hairless apes. A few will stand before the multitude, beaming with pride or shaking with nervousness (as the case may be), and present the latest research in contemporary ape thought. As their vocalizations reach a crescendo, those sitting demurely below will produce flesh-slapping noises that indicate they were paying attention (even if they weren’t). Another ape will then rise and this process will continue repeatedly and at length. It looks a lot like the modern political stump speech.

Increasingly, however, the rooms become more and more sparsely attended. Apes are social creatures and prefer to be directly involved rather than remain as passive observers. At this point you will be more likely to find them in various social groups imbibing stimulating drinks (those made from the waste product of yeast or from various South American bean species are the most popular). Now in their natural habitat, they produce vocalizations of their own. They might briefly reference one ape presentation or another, but will quickly move towards social grooming. For this, as all primates understand, is the main purpose of the conference.

“Alliances are established and maintained by grooming, the most social activity in which monkeys and apes engage,” wrote Oxford evolutionary anthropologist Robin Dunbar in his book Grooming, Gossip, and the Evolution of Language. “In some species, as much as a fifth of the entire day may be spent grooming, or being groomed by, other group members.”

By meeting other apes in your field, rifling metaphorically through their fur, and establishing closer bonds of friendship it serves to foster your connection with others as a social primate. Some are alpha members of their troop who are important to know; they may be in a position to bring you in and connect you with other influential apes if they’re suitably impressed. Others have information that may help you deal with issues in your own troop and, by connecting with them, it serves both of your interests. Still others simply enjoy the sense of belonging that comes from forging stronger bonds with fellow group members who they may not have seen in awhile. You can call it socialization, community building, or democracy. The bottom line, however, is that conferences are about one thing and one thing only: social grooming. Observing apes at the podium is just the excuse that brings them all together.

I recently attended Science Online, the annual fusion of science and social media held annually in Raleigh, North Carolina. Science Online, now in its sixth year, is a labor of love founded by Bora Zivkovic and Anton Zuiker based on the concept of the unconference. What this means is that social grooming has been built into all aspects of the event. Each session is organized by whichever group members feel motivated to do so and, rather than present themselves as the possessors of all ape wisdom, the moderators serve as guides who help to direct the participatory discussion in a useful direction (or at least prevent it from becoming derailed). The unconference is built around the following principle:

The sum of the expertise of the people in the audience is greater than the sum of expertise of the people on stage.

Traditionally, such participatory organizing has only been possible by using the social media tools that allow those living in different cities, as well as different countries, to interact in a common forum. It should therefore come as no surprise that Science Online, as well as other unconferences that have developed over the years (such as SciFoo, BarCamp, or THATCamp) have been composed largely of people who are tech-savvy. But this is changing and has increasingly been applied to local DIY workshops and skillshares in cities from Brooklyn to Berkeley.

More recently this model of organizing has taken on a political dimension. Politics, after all, is a social activity. In 2009 Chris Hutchins developed the idea for LaidOffCamp in San Francisco, a workshop organized and attended by the newly unemployed to share skills ranging from how to live more simply (and cheaply) to job hunting techniques in a moribund economy. The idea quickly expanded and LaidOffCamp events went on to be organized in New York, Chicago, Miami, Las Vegas, Phoenix, Los Angeles, and Salt Lake City (among others). But last year participatory organizing went mainstream. Occupy Wall Street used this same approach by making the person on stage a facilitator rather than a leader. By accepting proposals from the crowd, amplified by the human microphone in which those nearby repeat each sentence so that others can hear, the facilitator plays the role of fostering consensus on a course of action from the group as a whole. Harkening back to the motto of the populist Louisiana Governor Huey P. Long, crowdsourcing makes “Every man a king, but no one wears a crown.”

It is also the most natural form of organizing. As a species we evolved to thrive in social groups of just a few hundred individuals and “leadership” was a shifting notion that was based on merit and prestige. It was only with the invention of agriculture about 12,000 years ago that large, sedentary societies with firm hierarchies emerged and, along with them, a class of self-proclaimed experts. Hereditary god-kings, surrounded by a coterie of advisors and sycophants, became the perverse exaggeration of those loosely structured hierarchies that existed in our hunter-gatherer forebears. Merit was replaced by privilege and prestige could be inherited or bought instead of earned. Decisions were always top-down, representing the interests of those in power and only occasionally everybody else. Modern institutions–whether governmental, religious, commercial, or academic–are the inheritors of this vertical form of organization. The benefits of participatory, or “horizontal”, organizing are that it more closely approaches the interests of those directly affected by the decisions being made, whether these are government and private industry employees or concerned citizens. The unconference is the horizontal approach to education.

For Science Online, as well as the other unconferences or skillshares that have emerged in recent years, the ultimate result is a more informed and actively engaged audience. It is when social grooming is fostered that our species truly thrives. “One of the most important hallmarks of an unconference are meaningful and productive conversations—whether they take place in large groups, small groups, or between two or three attendees,” wrote Ethan Watrall, Assistant Professor of Anthropology at Michigan State University in The Chronicle of Higher Education. “I think that unconferences fill an extremely important niche in the scholarly ecosystem.” These are conversations that continue long after the physical event has ended, something I can’t say for the more traditional approach that conferences usually take. After attending Science Online for five years in a row now, I can assure you that this is one ape who is eagerly looking forward to #scio13.

"The Anatomy Lesson of Homo sylvestris" by Nathaniel Gold

Whether we are exploring our family genealogy or the genetic tree of our primate ancestors, all of us have a common yearning to know from whence we came. Origin stories captivate our imagination and offer a narrative structure for better understanding where we are today. The reality is that a knowledge of the history of science can both challenge our present and inspire the future.

Last year Tom Levenson, professor of science writing at the Massachusetts Institute of Technology, put together a panel on the Uses of the Past that was held at the World Conference of Science Journalists in Doha, Qatar. The panelists included Deborah Blum, Jo Marchant, Reto Schneider, and Holly Tucker who led an inspiring discussion about how the history of science has been useful to science writers and journalists, as well as being an important discipline unto itself.

However, the conversation was far from complete and I’ve been fortunate enough to join Tom this year to discuss the topic at Science Online 2012 (follow the discussion on Jan. 19 from 1:30 – 2:15 pm EST at the #scio12 hashtag on Twitter). In preparing for this discussion Tom and I have emailed back and forth our hopes for this session. One thing that has stood out is that where Tom thought of the term “uses of the past” as a challenge to writers about science for the public, an opening into approaches that will make their work better, I’ve been thinking about the importance of historical thinking to the practice of science itself – what working scientists could gain from deeper engagement not just with the anecdotes of history, but with a historian’s habits of mind. So just to get everyone’s juices flowing, Tom and I thought we’d try to exchange some views. Think of this as a bloggy approach to that old form, the epistolary novel – in which we try to hone in on the ways in which engagement with the past may matter across fields right on the leading edge of the here and now.

Dear Eric,

I have to confess; I’ve never needed convincing about history; I’m a historian’s son, and all my writing, just about, has had a grounding in where ideas and events come from.

But all the same, it’s simply a fact that the professional scientific literature from which so many stories for the public derive seems, on first glance, to be as present-tense as it is possible to be. As I write this, I’m looking at the table of contents of my latest (January 6) digital issue of Science. In the “Reports” section – where current findings are deployed — there is nothing but the now and the near future under discussion. Just to pull up a few of pieces at whim: we can learn of the fabrication of wires on the nano-scale that obey Ohm’s law (an accomplishment its makers claim will support advances in both classical and quantum computing to come). We can read of a new measurement of the ratio of isotopes of tungsten (performed by some of my MIT colleagues in concert with researchers at the University of Colorado) that suggests (at least as a preliminary conclusion) that the terranes that make up the earth’s continents have remained resistant to destruction over most of the earth’s history. And then there is a report from researchers into that living genetics/evolution textbook, C. elegans, that adds yet one more telling detail within a broader understanding of the intertwined behavior of genetic and environmental processes.

All of these – and all the rest of what you can find in this issue of that journal, and so many others – tell you today’s news. Each of these could form the subject of a perfectly fine popular story. Yet none of these do or necessarily would as popular stories engage the history that lies behind the results.

That is: you could tell a story of a small step taken towards the goal of building a useful quantum computer without diving into either the nineteenth century’s investigation into the properties of electrical phenomena or the twentieth century’s discovery of the critical role of scale on the nature of physical law. You can talk about the stability of continents without recognizing the significance of that research in the context of the discovery of the intensely dynamic behavior of the earth’s surface. You certainly may write about mutation rates and stress without diving into that old fracas, the nature-nurture argument that goes back to Darwin’s day and before. This is just as true for the researcher as the writer, of course. Either may choose to ignore the past without impairing their ability to perform the immediate task at hand: the next measurement, the next story. All fine, and all legitimate

You could, that is, but, at least In My Humble Opinion, you shouldn’t. From the point of view of this science writer, history of science isn’t a luxury or an easy source of ledes; rather, it is essential for both the making of a better (competent) science writer, and in the production of science writing that communicates the fullest, most useful, and most persuasive account of our subject to the broad audiences we seek to engage.

In briefest form, I argue (and teach my students) that diving into the history of the science one cover trains the writer’s nose, her or his ability to discern when a result actually implies a story (two quite different things). It refines a crucial writer’s tool, the reporter’s bullshit detector. At the same time, explicitly embedding historical understanding in the finished text of even the most present-and-future focused story is, I think, more or less invaluable if one’s goal is not simply to inform, but to enlist one’s readers in gerunds of science: doing it, thinking in the forms of scientific inquiry, gaining a sense of the emotional pleasures of the trade. I’ll talk more about both of these claims when my turn comes around…but at this point, I think I should stop and let you get a word in edgewise. Here’s a question for you: while I can see the uses of the past for writers seeking to extract from science stories that compel a public audience – do working scientists need to care that much about their own archives. What does someone pounding on C. elegans stress responses, say really need to know about the antecedents of that work?

Best,

Tom

Dear Tom,

The British novelist, and friend of Aldous Huxley, L.P. Hartley began his 1953 novel The Go-Between with a line that, I suspect, many working scientists can relate to, “The past is a foreign country: they do things differently there.” The process of science, much like the process of art, is to dredge through what has been achieved in the past in order to generate something altogether new. That is perhaps the only thing that the two fields of creative endeavor have in common; the past must be understood only so that you can be released from it. However, much like you, I’ve never needed convincing about history either. While I agree that the past can be a foreign country at times, I’ve always enjoyed traveling.

I came to history through my work in science, but I found that understanding the historical context for why scientists in the past came to the conclusions they did helped inform the questions I was asking. I’ve always believed that the scientific method was the best way of eliminating our own personal biases when seeking answers about the natural world, but that unexamined assumptions can still slip through the scientific filter. By examining how these flawed assumptions made it through I hoped it would help me in my own work. Perhaps the best way to explain what I mean by this is to briefly discuss how an early brush with history encouraged me into the research direction I ultimately pursued in graduate school. The book was Nature’s Body by the Stanford historian of science Londa Schiebinger that I found in a used bookstore during my senior year as an undergraduate in anthropology and biology. In one chapter of her book she discussed the early history of primate research and how the prevailing assumptions about gender influenced the hypotheses and, as a result, the conclusions about those species most similar to ourselves. One of the earliest descriptions of great apes in the West, after Andrew Battell’s exaggerated stories about “ape monsters,” was by the Dutch physician Nicolaes Tulp, probably the most widely recognized figure in the history of science that almost no one has ever heard of.

Homo sylvestris from Tulp's Observationes Medicae

In 1632 Tulp commissioned the artist Rembrandt to paint his anatomy lesson, which ended up being one of the Dutch master’s most famous works (if anyone today recognizes Tulp’s name, it’s most likely from the title of this painting). Nearly a decade after he posed for this portrait Tulp published his Observationes Medicae (Medical Observations) in which he described the anatomy of a female ape he’d received on a ship bound from Angola. He was immediately struck by the similarities with humans and the drawing he published, identified as Homo sylvestris, demonstrated a striking example of cultural bias. Made to look the way he assumed this female would appear while alive, Tulp emphasized his own culture’s gender stereotypes. The female sat with her hands in her lap, framing what appeared to be a pregnant belly, and her head was glancing downwards in a distinctly demure pose.

By itself this depiction wouldn’t have been particularly revealing; it was just one individual allowing their own social biases to influence his science. What was remarkable, however, is the way Schiebinger showed how Tulp’s depiction would appear time and time again in the subsequent centuries when describing female primates, not just in appearance but also in behavior. More than two hundred years later, when Darwin described the differences between males and females in his theory of sexual selection, he had the same unmistakable gender bias that influenced his thinking. I had never taken a women’s studies course in my life, but this insight was an enormous wake up call for me. I realized there had been a common set of assumptions that endured for centuries, what the historian Arthur Lovejoy called “the spirit of the age,” and had gone unexamined until relatively recently when a new generation of primatologists–such as Jane Goodall, Sarah Blaffer Hrdy, and Frans de Waal–began studying the female half of the equation that had been largely ignored as an important area of study. Knowing this history pushed me to ask different questions and focus on a topic that I discovered hadn’t been addressed before: why female bonobos had such high levels of cooperation despite the fact that they had a low coefficient of genetic relatedness (violating the central premise of Hamilton’s theory of kin selection). Different scientific topics have their own entrenched assumptions that otherwise critical researchers may not have considered; that is, until they see the broad patterns that a historical analysis can reveal.

Cheers,

Eric

Dear Eric,

I love your story, partly because the original painting is so extraordinary and it’s good to have any excuse to revisit it. But I value it more for your argument that engaging with the thought and thinking (not quite the same thing) of scientists past fosters insight into present problems. That goes just as much for science writers – that is to say, those seeking to communicate to a broad public both knowledge derived from science and the approaches, the habits of thought that generate those results.

Rembrandt’s painting itself gives some hints along this line. There’s a marvelous and strange discussion of the work in another novel written in English, W. G. Sebald’s The Rings of Saturn. There, Sebald points to the fact that none of the anatomists are actually looking at the corpse under the knife. Tulp himself stares out into the middle distance, whilst other members of his guild peer instead at an anatomical atlas open at the foot of the table. As Sebald studies the one of the often-discussed details of the painting, he argues that what appears to be simply an error in the depiction of the dissection of the left hand reveals an artist seeking to see past the formal abstraction of the lesson, drawing attention instead to the actual body on the table, the physical reality of a single dead man.

Not wishing to push too hard on that (unproven, unprovable) interpretation, Sebald still points out something that rewards the attention of science writers. Rembrandt depicts both facts — the body, the tendons of the exposed hand – and ideas, at a crucial moment of change in the way natural philosophers sought verifiable knowledge.

We see, amidst the reverence for the book, the authority of prior learning, an event actually occurring on the canvas: the effort to extract understanding from the direct testimony of nature. Amidst all else that can be read there, Rembrandt’s painting reminds the viewer of the time – not really all that long ago – when a fundamental idea was being framed with its first answer: yes, it is possible to understand biological forms as machines, and to investigate their workings directly.

So, to take the long road home to the question of why bother with history when covering the news of today and tomorrow, here are two thoughts (of the three with which I will hope to provoke our fellow unconferees on Thursday). First: as you argue for scientists, understanding of the past can lead writers to stories they may not have known were there.

To give an example, I’ll have to leave anatomy behind (about whose history I sadly know very little). I recently had an occasionto look back at A. A. Michelson’s infamous remark from 1894 when he asserted that physics was done except for that which could be discovered in the sixth decimal places of measurements.

There is a lot wrong in that claim, but if you look more closely at what he said, you can find something less obvious in Michelson’s claim – and that can lead to insight into what goes into the making of all kinds of very modern physics, from (possibly true) observations of faster than light neutrinos to the ways in which cosmologists are extracting knowledge from high-precision measurements of the cosmic microwave background (and much else besides, of course).

So there’s a story-engine chugging away inside history, which is there to be harnessed by any writer – facts, material, from which to craft story. There’s also a story-telling tool, a method that derives directly from historical understanding. A core task for science writing is the transformation of technically complicated material into a narrative available to broad audiences – which must be done without doing violence to the underlying ideas. If the writer remembers that every modern problem has a long past, then she or he can prospect through that history when the problems and results in that sequence are intelligible to any audience. For just one last, very quick example: general relativity is a hard concept to explain, but framing the issue that it helped to resolve in the context of what Newton’s (seemingly) simpler account of gravity couldn’t handle – that spooky action at a distance that permits the gravitational attraction of the sun to shape the earth’s orbit – and you’re in with a chance.

Best,

Tom

Dear Tom,

I think you touched on something very important with regard to the idea that science writing is a transformation that takes the technical language of science (primarily mathematics and statistics–that is, if it’s done correctly) and interprets it into the communication of everyday experience. Science writing is a process of translation. The history of science as a discipline is precisely the same thing, though historians typically engage in a different level of linguistic analysis by looking at language meaning and the way that science provides insight into the process of historical change. But it seems that there is no better way to think about how the history of science can be useful to science journalists than to consider what we do as essentially a process of translation. Art is involved in any translation work and there is never a one-to-one correspondence between the original and what it eventually becomes. We must be true to our source material but also evoke the same overall meaning. To put this more simply: why are the findings being reported important to scientists in a given field and how can that same importance be conveyed to a readership with a very different set of experiences? It seems to me that there are two primary ways of doing this: engaging with the history of why this question matters or tapping into contemporary attitudes that evoke connections with the findings reported (where the latter approach goes wrong happens to be one of my favorite topics of critique, one that is unfortunately an extremely rich resource to draw from).

However, there is one other reason why the history of science is important for science journalists that we haven’t quite touched on yet. A journalist who knows their history is better protected from false claims and the distraction of denialism. The scientific press release is a unique cultural invention and all too often seeks to manipulate journalists into framing a given story so as to exaggerate that study’s actual impact. The historically minded journalist is less likely to get bamboozled. In a similar way, the he said-she said model of reporting is a persistent and irritating rash for almost every professional journalist I’ve interacted with. But the temptation to scratch is always present, even though the false equivalency reported is rarely satisfying over the long term. The history of science can be the journalistic topical ointment. Those who know the background of anti-vaccine paranoia, or who recognize the wedge strategy of creationist rhetoric, can satisfy their need to report on a story that captures the public’s attention while also providing useful information to place that issue within it’s proper context. History matters.

Your friend,

Eric

   "Elementary" by Nathaniel Gold

If reproductive success were applied to fiction the two billion copies of Agatha Christie’s novels (only trailing behind Shakespeare and the Bible) would be considered a stunning example of evolutionary fitness. Her work, in such classics as Murder on the Orient Express, Death on the Nile, or Witness for the Prosecution represents a significant portion of our collective memory that is being passed on to future generations. However, researchers have recently uncovered evidence of a tragedy that befell the world’s most popular mystery writer and, in so doing, provided a useful lesson when considering genetic evidence for the evolution of human sexuality.

Ian Lancashire and Graeme Hirst at the University of Toronto analyzed the vocabulary used throughout Christie’s writing career and determined that the sophistication of her language underwent a significant decline in her final years. By looking at the number of different words used in her novels, as well as the number of repeated phrases, the researchers determined that her vocabulary dropped by almost 31% with the largest decline occurring in her last four books. This, in combination with her family’s testimony about undiagnosed physical and mental decline, led the researchers to conclude that they were witnessing the effects of Alzheimer’s disease on the world’s best-selling author. As a result, Christie’s final novels maintained echos of her former work, but they were of a substantially different character to most of her 54-year career as a writer.

Imagine for a moment that everything Agatha Christie had ever written was lost to history except for her last book. If you were to try and form conclusions about her work from this limited account it would result in significant distortions. It would represent the author after she had undergone a profound change and you would be hard pressed to understand why she had ever been so popular. But this kind of selection bias is essentially what we have when we look at the written record of our human past. All of written history, from the earliest accounts in 3,200 BCE to the present, is a mere fragment of human existence on this planet. It is the equivalent of only looking at Agatha Christie’s final novel out of 85 published works during a long and distinguished career.

There is no greater mystery in human evolution than the origins of our sexuality. Following the trail of clues available researchers have independently concluded that humans evolved through systems of monogamy, polygamy, as well as polyamory. However, only one can be the culprit. Like a detective interrogating multiple suspects, the solution ultimately depends on which account you’re willing to believe.

In 2009 Owen Lovejoy made the case for monogamy based on the fossil remains of the early human ancestor Ardipithecus ramidus. Meanwhile, Christopher Ryan and Cacilda Jethá have argued that polyamory (or, more precisely, a multimale-multifemale mating system) is the most likely scenario from an analysis that emphasized anthropology, behavioral biology, and physiology. To further complicate matters the third suspect in this mystery, polygamy, has been the conclusion from scientists conducting DNA analyses. These conflicting accounts therefore require careful detective work in order to determine which story is the most convincing.

Polygyny (the single male-multifemale version of polygamy) is most well known among primates such as baboons or gorillas. These are the species that have been (incorrectly) described as living in “harems,” and are often easy to identify since the males can be up to twice the size of females. Many anthropological accounts, most famously George Murdock’s Ethnographic Atlas, have suggested that the human species is “moderately polygynous” since the majority of studied societies practice polygynous marriage (982 out of 1157 according to Murdock’s account).

To test whether these reports of polygyny are a local or species-wide phenomenon evolutionary biologist Michael F. Hammer and colleagues at the University of Arizona published their findings in the journal PLoS Genetics. By analyzing the clues left in our X-chromosomes and comparing their results to human autosomes (any of the additional 22 chromosome pairs that aren’t sex-linked) the researchers sought to discover what they call male vs. female “effective population size,” or the percentage of males compared to females who were effectively reproducing. If polygyny were indeed the norm it would mean that most men throughout human evolution never reproduced and, in strictly genetic terms, had mysteriously vanished without a trace.

Because women have two X-chromosomes they will always pass one of these to either their son or their daughter. Men, on the other hand, will either pass along an X-chromosome (in the case of a daughter) or a Y-chromosome (if they’ve had a son). But both men and women pass along the same number of autosomes. This means that by comparing the genetic differences between X-chromosomes and autosomes you can estimate the effective population size of men who successfully reproduced compared to women. In other words, the genetic evidence for effective population size is being used to determine the mating system. Skewed upwards and only a few men in any given population were having children with multiple women as in polygynous systems. However, if the ratio is closer to 1:1 it would be consistent with monogamy since an equal number of men as women were passing on their genes.

Ratio of effective population sizes between X-chromosomes (Nx) and autosomes (Na) for each population. Points above the dotted line suggest greater variability in male reproductive success. Figure reproduced from Hammer et al. (2008).

Mike Hammer and his team of genetic detectives therefore analyzed the chromosomes from six different societies: French Basque, Han Chinese, Melanesian islanders from Papua New Guinea, Biaka foragers from Central African Republic, Mandenka villagers from Senegal, and San hunter-gatherers from Namibia. The researchers found evidence that there was greater variability on the X-chromosome than would be expected if monogamy had been the standard practice. Instead, the evidence suggested a male-female ratio of relatively few men and multiple women as would be expected in polygyny (ranging from 2.4-to-1 among the San and 8.7-to-1 among the Basque). This genetic evidence by Hammer and colleagues would seem to support Murdock’s data on marriage systems and confirm that polygyny was the dominant mating system during human evolution.

But like every good detective mystery, just when you think the case is closed you’re treated to a twist ending. Primatologist Sarah Blaffer Hrdy (author of The Woman That Never Evolved, Mother Nature, as well as her latest book Mothers and Others) is one of the leading experts on polygynous mating systems in primates. As she explained to me in our recent correspondence there are several important considerations that have been left out of this story. The most important is the kind of sample bias I referred to earlier if we were to make conclusions about Agatha Christie’s work based only on her final novel. The DNA evidence may be a record of the human past, but how far into the past does it actually go? As Hrdy explained:

Keep in mind that in terms of interpreting such genetic evidence we are of necessity confined to a fairly recent time depth (and remember, by “recent” someone like me means the last 10,000 years or so). For this time period multiple lines of evidence do indeed suggest that humans were moderately to extremely polygynous and that women were moving between groups more than men were.

Humans have been around for far longer than 10,000 years and conservative estimates place the emergence of modern Homo sapiens at about 200,000 years ago. A genetic record extending back 10,000 years is remarkable, but it’s essentially adding only three more novels to our existing timeline.

There is also something very important to consider that dramatically influenced human behavior within the last 10,000 years: the invention of agriculture. Prior to about 12,000 years ago all humans were hunter-gatherers and lived a migratory existence. With the advent of farming some human societies began to remain sedentary for the first time in our history. This change had serious impacts on human life and behavior. Just as Alzheimer’s dramatically altered the content of Agatha Christie’s work, so agriculture radically transformed human society and, by consequence, sexual behavior.

Hrdy argues that there was a major disruption in human residence patterns as a result of this “agricultural revolution.” In small bands of modern day hunter-gatherers there is a mixture of what anthropologists call matrilocal and patrilocal residence, the practice of women or men to stay within the community they’re born into while the other migrates between communities. However, recent research has shown that hunter-gatherer societies today emphasize matrilocal (or bilocal) residence while fewer than 25% are considered patrilocal. This is in stark contrast to the larger scale agricultural societies where an estimated 70% are patrilocal.

According to Hrdy, pre-agricultural human societies would likely have been similar to modern day hunter-gatherers, but the rise of agriculture changed this pattern dramatically. Over the past 10,000 years or so, Hrdy explained, “matrilocal societies gave way to pressures from more expansionist patrilocal societies.” This simple change had serious repercussions for both human life and the genetic record. Patrilocal societies typically show increased hierarchies, greater male control over women’s sexual choices, and more competition among men compared to matrilocal societies. Patrilocal societies are also usually polygynous. Therefore, the larger numbers of patrilocal (and polygynous) societies today is likely the consequence of agriculture and not a true reflection of the human past. Like Agatha Christie’s writing, many human societies underwent a dramatic transformation and basing our conclusions on this period would distort our understanding of what came before.

But there is an even more basic problem in assuming a polygynous human mating system. Modern day bonobos and chimpanzees have a male vs. female effective population size of between 2-to-1 and 4-to-1. If we were using the same argument presented by Hammer and colleagues, these two species should be considered “moderately polygynous” as well. Two independent genetic studies found both bonobos and chimpanzees to be similar to humans on identical criteria. As one study (Erickson et al., 2006) concluded, “the male effective population size in bonobos is small and similar to that suggested from comparable data in humans,” while, in the second study (Langergraber et al., 2007), the “data indicate that the sex difference in effective population size is similar in chimpanzees and humans.” It turns out that our would-be perpetrator has two reliable alibis.

Despite Pan‘s moderately polygynous genetics, the bonobo and chimpanzee mating system is most accurately described as multimale-multifemale because males and females each mate with multiple individuals. Of course, this isn’t random or indiscriminate mating since females are making careful decisions about who they choose to mate with, and when. The effective population size in bonobos and chimps shows up looking genetically similar to humans because females choose to preferentially mate with high-ranking males during their peak of ovulation. Females still choose to mate with additional males at other times of their cycle, but since these don’t produce offspring the end result is that relatively few males are passing on their genes. As Hrdy has demonstrated, something very similar has been shown among humans. This makes a multimale-multifemale mating system the prime suspect in our evolutionary whodunit.

In humans, bonobos, and many other primates, there is a great deal more non-conceptive sexual behavior going on than most people — from Saint Augustine to contemporary biologists – realize. For example, in South American partible paternity societies, the woman’s official mate or husband is still statistically more likely to be the progenitor of offspring she produces, even though other men can and do have some probability of paternity, or at the very least, perceive that they do.

Because of this, Hrdy notes, in a large number of human societies women may be having multiple sexual partners at any given time, but there will usually be a relatively small number of men who are the actual fathers of their children. In this way the missing persons in our evolutionary mystery would be the result of sample bias. It’s not because our genes don’t reveal the full story, it’s because women have only chosen some men whose genetic tale they wanted future generations to remember. In the evolution of human sexuality, as it was in Agatha Christie’s life and work, such stories can be subject to dramatic alterations depending on the circumstances and care must be taken lest we misinterpret and obscure the very mystery we’re trying to solve.

This post originally appeared at Psychology Today.

References:

Hammer, M., Mendez, F., Cox, M., Woerner, A., & Wall, J. (2008). Sex-Biased Evolutionary Forces Shape Genomic Patterns of Human Diversity PLoS Genetics, 4 (9) DOI: 10.1371/journal.pgen.1000202

Burton, M.L., Moore, C.C., Whiting, J.W.M., & Romney, A.K. (1996) Regions Based on Social Structure. Current Anthropology, 37(1), 87-123.

Eriksson, J., Siedel, H., Lukas, D., Kayser, M., Erler, A., Hashimoto, C., Hohmann, G., Boesch, C., & Vigilant, L. (2006) Y-chromosome analysis confirms highly sex-biased dispersal and suggests a low male effective population size in bonobos (Pan paniscus). Molecular Ecology, 15(4), 939-949. DOI: 10.1111/j.1365-294X.2006.02845.x

Hrdy, S.B. (2005) Cooperative Breeders With an Ace in the Hold. In Voland, E., Chasiotis, A., and Schiefenhövel, W. (Eds.), Grandmotherhood: The Evolutionary Significance of the Second Half of Female Life. New York: Rutgers University Press.

Hrdy, S.B. (2000) The Optimal Number of Fathers. Evolution, demography, and history in the shaping of female mate preferences. Annals of the New York Academy of Sciences, 75-96. PMID: 10818622

Langergraber, K., Siedel, H., Mitani, J., Wrangham, R., Reynolds, V., Hunt, K., & Vigilant, L. (2007) The Genetic Signature of Sex-Biased Migration in Patrilocal Chimpanzees and Humans. PLoS ONE, 2(10), e973. DOI: 10.1371/journal.pone.0000973

Marlowe, F.W. (2004) Marital Residence Among Foragers, Current Anthropology 45(2): 277-284.

  "Carl Zimmer" by Nathaniel Gold

Carl Zimmer has an uncanny knack for getting under your skin, quite literally. While travelling through the village of Tumbura in southern Sudan he encountered invisible monsters that live inside the subcutaneous tissue of their innocent victims. Under a microscope these creatures, known as Onchocerca volvulus, resemble coiled worms. As they crawl through your flesh they provoke an immune response that leaves an itchy rash all over. People have been known to scratch themselves to death. Later, they crawl through the outer layer of your eyes causing blindness. In Tumbura nearly everyone over the age of 40 had gone blind as a result of these parasites.

This is just one of nature’s bizarre creations that Zimmer has spent more than a decade exploring. His writing projects, whether in books like Parasite Rex and Soul Made Flesh, at his award-winning blog, or in regular features for The New York Times, are as fascinating and provocative as the subjects he covers. He is, at the same time, the busiest science writer working today and the one who most consistently pushes boundaries to communicate science in a way you’ve never experienced before.

As shown in part one of this interview, Carl Zimmer has entertained and informed readers for more than a decade. His latest books, all released this year, have found new ways to get under the skin of readers. A Planet of Viruses examines the fascinating world of virology and delves to new levels in the world of the very small. Meanwhile, Science Ink explores the tattoo art of the science obsessed and illustrates the passions that drive scientists to search just beneath the surface of current knowledge. His two e-books, Brain Cuttings and the aptly titled More Brain Cuttings, dig deep into his unpublished archives to expose nature’s marvels to the light of electronic paper. It is a collection of work that reveals just how fortunate we are to have a science writer like Carl who possesses such passion and efficiency.

Planet of Viruses is Zimmer's third book on microbiology after Microcosm and Parasite Rex.

Eric Michael Johnson: You’ve been extremely prolific this year. You’ve published two e-books and two hardcover books, one of which is called A Planet of Viruses. It reads almost like a collection of love letters about some of your favorite infectious pathogens. Influenza, West Nile, Ebola, smallpox; each get their own chapter where you emphasize the wonder and mystery of what most people would consider a scourge on humanity. You even write about how if you close your eyes and say the word aloud, “influenza” sounds lovely. I think you’re right. This is your third book on microscopic parasites. What is it about this topic that you find so fascinating?

Carl Zimmer: There’s something endlessly fascinating in biology about the fact that there’s this huge invisible world of things that are incredibly important and sophisticated and highly evolved but that we don’t think about much in our daily life. My first way of exploring that was with my book Parasite Rex. Then, a few years later, I was thinking a lot about the old question “What is life?” I was fascinated by how scientists were starting to address this question in some very specific ways. They were able to start laying out an organism’s entire network of genes and show how they interact. It occurred to me that most of this work had been done with just one species of bacteria, E. coli. Most people, if they’ve heard of E. coli, just think that it’s something they should avoid in their hamburger. And yet, in a lot of ways, modern biology is built on this organism. That was the inspiration for my other book Microcosm.

What was funny then is that I didn’t think I could get much more microscopic. But recently I was invited to get involved in an education program about viruses. What I started to do was write essays about individual viruses and try to use these essays to talk about some general developments in this whole science of virology. I was really quite floored by the things I was discovering. For example, there are 10 to the power of 31 viruses on Earth, or 1 followed by 31 zeros. That’s way beyond any other kind of life form. I also discovered that the majority of the genetic diversity on Earth is in the genes of viruses. It was astonishing to me. There was this whole world of viruses that I hadn’t fully appreciated. Now I think that virology is really the most exciting branch of science these days. There is so much that’s happening.

Johnson: There is a certain irony that your second hardcover book published this year could, if it’s done incorrectly, actually be the cause of infectious disease.

Zimmer: [Laughs]

Johnson: With Science Ink, what was the biggest surprise as you began receiving the hundreds of photographs of scientifically-inspired tattoo art?

Zimmer: I just think the fact there were hundreds of pieces of scientific tattoo art was surprising in itself. I had no idea this would happen. I just noticed one neuroscientist with a DNA tattoo on his shoulder and I took a picture of it to post on my blog. With it I just asked an open question about whether there were other scientists out there. I thought it was funny enough that there was just one. Then, lo and behold, there were actually hundreds upon hundreds of people with these tattoos. But what became interesting was how much these tattoos could tell. A lot of times people would get tattoos about the science that they studied. Maybe it was a particular type of neuron that they did their PhD on, or it was the mathematical equation that governs all their research. It was this totally different way of probing the passions of scientists.

Zimmer announcing the release of Science Ink on social media. / Carl Zimmer 2011

Johnson: I suspect the word “scientist” brings to mind a very specific image for most people, one that probably doesn’t include someone with a tattoo that covers their entire back. Throughout your work you have sought to bring science home and emphasize that scientists are largely doing what we all do. They’re sorting out the ideas that work from the ones that don’t, just at a more precise level. It’s what the biologist Thomas Henry Huxley called “organized common sense.” Are you concerned about the public perception of scientists, and science more generally? How does this factor into your work?

Zimmer: I think that, for the most part, people feel that scientists are some other species. They don’t know scientists personally and largely just read about what they do or see them on TV. There’s definitely a gulf there. I think it can be a valuable thing to show scientists as they are, as human beings.

In a sense what I try to do in all my writing is to help readers become better scientists themselves. If you’re walking through the woods and you happen to see some weird little colored blobs on a log you might just walk past and not think about it at all. But those are what are known as slime molds. If you’re a scientist that studies slime molds they turn out to be immensely fascinating things, some even spend their entire lives studying them. So when I write about slime molds I want readers to become curious so that the next time they’re out in the woods they’ll stop and take a closer look. I want them thinking about the same questions that the scientists are asking. What is this thing? Is there a weird intelligence to this blob as it probes around on the forest floor and sucks up food? Does this slime mold tell me something about how my own ancestors came on land? So, to answer your question, yes, public perception is an important concern for me.

Johnson: There are now so many new ways to communicate science directly with the public. Blogs, social media, and now e-books have offered a unique interaction between writer and audience. You have already been blogging and tweeting for many years, but 2011 marked your first exploration into e-book publishing with your collection of essays entitled Brain Cuttings. In all of these different mediums do you find the message itself changes? What would be your advice for writers looking at the diversity of options available to them?

Zimmer: My advice at this point would just be to experiment and to find things that work well for you as a writer. I just came out with a second collection of pieces called More Brain Cuttings. It’s not a very exciting title. [Laughs] But after doing two of these things now I still don’t feel that I have the answers sorted out. It’s been interesting to experiment with this and it’s been nice to create another way for people to read some of my stuff, but I think there a lot of serious questions about whether science e-books will be particularly successful as a way for reaching people. There are still a whole lot of stumbling blocks put in people’s way and we’ve got to keep experimenting and figuring those things out.

That being said, I guess my advice would be that the goal of science writers should not be to become a science journalist circa 1980. That doesn’t exist anymore. A lot of people may mourn the loss of that kind of science writing, when staff writers on city newspapers and magazines would produce regular articles. There was a lot of good that came out of that model, but the fact is that it’s gone. What’s taken its place is very chaotic. But I think that for people who want to experiment and play around with software or genres, they can help to discover something brand new about how to write about science.

Carl Zimmer with biologists Niles Eldredge, Paul Roossin, and Rick Lipkin / Josh Rosenau 2010, Flickr

Johnson: With the advent of blogs there developed a now well-established genre of doomsaying about the future of books and long form writing in general. Do you give any credence to those who bemoan what is sometimes called “short attention span theater” (and, if you could, please answer in 140 characters or less)?

Zimmer: [Laughs] Yeah, right. There has been a lot of doomsaying and I think that the most extreme doomsayers need to retract everything they’ve said. It’s just not true. People are still reading books. Maybe a quarter of them are reading these books on their phones, but they’re still reading books. There’s a whole flourishing niche of what people call #longreads where people will write pieces that are thousands of words long and put them online. You have places like The Atavist putting out really long reads that are 20,000-30,000 words. They’re not long enough to be conventional books but they’re way too long to be traditional magazine pieces and people are snapping them up.

I think people were just so scared of all the new possibilities that were opening up that they were sure it was all going to end badly. Of course there’s a lot of garbage out there. I’m not going to dispute that. As readers we have to discipline ourselves about how we read. There’s always something vaguely interesting just another click away and we have to structure our time if we don’t want to get swept along in a flood. But that’s different than saying that long form writing is dead.

The flip-side of that is Twitter. For the life of me I can’t understand people carping about Twitter. They keep getting confused between the system and what people are writing on it. The fact that you can only write 140 characters does not mean that, by default, everything people write on it is unimportant. I’ve literally seen people say, “Everyone tells me as a journalist that I need to be on Twitter, but I don’t want to be writing about what I ate for breakfast.” No one’s forcing you to tell us what you ate for breakfast on Twitter. You could actually look at it as an experiment or an opportunity to be creative, a way to distill things down to very short and sweet statements. It’s like bemoaning haikus by saying that they’re so short and it will be the death of poetry. That would be exactly the same thing. It’s just silly.

Johnson: This seems to tie in with the old debate about whether blogging is journalism. Are you optimistic about what blogging has done for the profession?

Zimmer: Absolutely, that debate is over. Let me give you a personal example. I was asked to give a talk last year at a scientific conference. It was very intimidating because I’m a journalist and here I was being asked to stand up in front of a bunch of scientists. I had no idea what I was supposed to say. What I decided to do was to take advantage of the strength that we science writers have, which is that we’re not stuck in one tiny sub-specialty. We move around, we talk to lots of different people, and we can see connections sometimes that they might miss. My talk was addressing people who were working on genome sequencing and looking for important patterns that might lead to the development of drugs or identify the causes of disease. I tried to get them to think like ecologists. I explained that health is an ecosystem, it’s not whether we have a particular gene or not. I developed this talk about all the microbes that live in us, the microbiome, and I thought it worked out pretty well.

But afterwards I felt very depressed. I worked so hard on this talk, I’d spoken to several hundred people, but then that was it. It was over. I really wanted to give this an extra life, so I sat down and started writing. I wrote everything down and even inserted some of my slides. This was not something that would have worked as a magazine piece. So I just stuck the whole thing, all five thousand words, up on my blog. I know there are people that would say this is too long for a blog post. But it became one of my most read posts of the entire year. The journalist Steve Silberman picked it as one of his five favorite longform pieces of 2011 and it’s going to be my contribution to the book Open Laboratory, the annual anthology of science blogging. So, for me personally, this gibberish about the death of long form writing is just that. It’s gibberish. This is a wonderful time to be a writer and there are endless opportunities to explore and innovate. It’s a lot of fun.

Click here for Part One: Carl Zimmer on the Art of Science Writing

Previous Interviews at The Primate Diaries:

• Frans de Waal on Political Apes and Building a Cooperative Society
• Lee Alan Dugatkin on Peter Kropotkin, Anarchism, and Cooperation in Nature

  "Carl Zimmer" by Nathaniel Gold

Carl Zimmer is one of the most insightful and trenchant science writers working today. Whether he is delving into the soul of the scientific revolution or exposing the precise horror of parasites to reveal our relationship with the natural world, he evokes a passion for his subject with a graceful clarity of style. Unlike his literary icon, Herman Melville, he doesn’t adorn his writing with ornate flourishes or complicated scaffolding. His approach is simple, elegant, and potent, much like the microscopic lifeforms he so often examines. And, like these microorganisms, he is a marvel of adaptability and innovation. He is a Kavli award-winning journalist, Yale University instructor, blogger, and author of twelve books. But that’s only skimming the surface.

For those who are professional science writers, or enthusiastic readers of the latest science news, the name Carl Zimmer is well known. But what may not be as widely known is his incredible generosity and the passion he feels for his subject. He has the ability to turn complicated scientific topics into engaging stories that uplift a reader who might otherwise feel intimidated. At the same time he makes scientists familiar by revealing their own passion for the subject and bringing readers closer to them through a shared curiosity. Quite appropriately, given the topic he often writes about, the result is infectious.

I first met Carl in 2007 at the annual ScienceOnline conference and have learned a great deal from him both through his written work and our scattered correspondence. While all writers are natural observers, Carl is someone who listens. It is this combination of a keen eye for detail and the generous patience of a good teacher that makes his work such a pleasure to read. I had the opportunity to talk with Carl last week to probe his own passion for the art of science writing. It is my hope that others can learn from him as I have so that, together, we may continue to push ourselves and find innovative ways of communicating our shared passion for scientific discovery.

Carl Zimmer at Koshland Science Museum, Washington, DC / Chris Suspect 2010, Flickr

Eric Michael Johnson: The National Book Award-winning novelist Joyce Carol Oates has written that one of the most important influences on a writer is their early failures. What was one of your most meaningful failures while you were learning to be a science writer?

Carl Zimmer: When I first started out I got a job at Discover magazine. I was very young and one of the first things they had me do was fact checking. I was given a story about the potential health risks of power lines, something that was a big controversy at the time. Someone had written an article for us and it was my job to make sure that it was right. I thought I had done a good job, but it turned out there was one detail I had overlooked. It was a number on some figure about cancer rates. This was about fifteen years ago so some of the memories are a little fuzzy.

But what’s not fuzzy is my memory of what happened next. The editor-in-chief, Paul Hoffman, called a staff meeting for the sole purpose of raking me, and the senior editor on the story, over the coals. He wrote the number on a big white board behind his desk and went completely ballistic about allowing those sorts of mistakes into his magazine. It was quite humbling. This was not calculus, it was just a simple number that I should have made sure was correct. The mistake cast a stain on the whole story because people knew it couldn’t be right and it caused them to question everything that came afterwards. That, for me, was a pretty big stumble and it was an incredibly important lesson. It showed me just how easy it is to make mistakes and for errors to creep into articles, especially articles about science. You have to take that extra step and double check everything. My experience at Discover really drilled that into me.

Johnson: Part of what I love about your writing is the infectious enthusiasm you display for the topic. Had you always known you wanted to write about science? At what point did it strike you that this is how you wanted to spend your life?

Zimmer: I definitely did not know early on that I wanted to be a science writer. I didn’t even know I wanted to be a science writer when I was actually working as a science writer. I knew I wanted to write when I got out of college, but I didn’t have a clear idea of what I would be. I was always very interested in science and would have taken many more science classes if they hadn’t all been at eight in the morning. Fortunately, science turned out to be a very good fit. I haven’t considered writing about anything else ever since.

Linsly-Chittenden Hall, Yale University where Zimmer received his degree in English, 1987 / GK tramrunner229, Wikimedia Commons

Johnson: When you were first developing your voice as a writer, who were some of your most important influences? I know you were particularly fond of Melville and Faulkner as an undergrad at Yale. What did studying literature offer for developing your own style compared to the work of other science writers?

Zimmer: At the time I was reading Melville, Faulkner, or Mark Twain, I had vague ideas about writing fiction. That was my initial impetus for reading them. Gradually I realized that I was actually more interested in the natural world. It was at that point I began to appreciate really good science writing. I was reading people like Jonathan Weiner, John McPhee, or David Quammen, writers who could construct a sentence that left you breathless. But it was very important for me to have had that different experience in reading beforehand. It taught me how important it is to tell a story when you’re writing as well as all the different ways you can tell that story. These are elements you can bring into science writing to great effect.

The fact is there is a lot of science writing in great literature. I’m a big fan of Moby Dick, for example. Melville’s novel is probably a quarter to a third science writing. It’s the story of an obsessed captain going after a whale interspersed with long passages about marine biology, paleontology, even consciousness. It’s all science. But he writes about it in a style that can be quite humbling. When you read it you see how beautiful someone can make these descriptions of the natural world. I’ve always been frustrated with the flatness of a lot of science writing. I think that science writers should try to aim high rather than going for a lot of these clichés you often see both in magazines and in books.

Johnson: That brings up a very interesting point. Communicating science offers some unique challenges for a writer. In fiction the exposition is usually hidden and the reader comes to understand a character through their actions. We’ll emotionally bond with that character and this pulls us into the story. But for so much of science writing, the science itself is the character. How do you effectively connect with a reader emotionally and, at the same time, provide the necessary scientific background to bring a reader up to speed?

Zimmer: That’s a great question. It’s really hard to articulate an answer to that because I tackle that challenge almost by a sense of touch or intuition. In terms of techniques for communicating that passion, I think part of what you have to do is make sure the beginning is completely captivating. You can’t start a piece with a lot of inside baseball. You have to remember that when you are writing about science you are ultimately writing about inherently fascinating and compelling things.

I just started reading a piece in the latest New Yorker about desertification called “The Great Oasis” by Burkhard Bilger. He could have gotten into a lot of technical detail right off the bat describing the various debates about the causes of desertification. But what he starts with is a beautiful account of what it’s like when it rains in Oman. He just describes how the rain rushes over the dry, stony surfaces in this relatively obscure country in the Middle East. It’s absolutely gorgeous writing. He simply provides the reader with an image. What he’s basically saying is, “Picture this. This is what I’m going to be telling you about.” Once you have people’s attention like that they will be willing to go with you a long way. It’s so important to bear in mind that big picture and not to get lost in the details. The details matter but they have to be fit into this larger scaffolding.

Johnson: Is it a matter of finding the emotional core of the story and opening with that feeling?

Zimmer: Yes. I don’t mean that you should be mawkish or sensationalistic, but every story about science has something that is truly absorbing. I think that’s what motivates the scientists themselves. Sometimes you can discover the way to frame a piece just be pushing scientists to explain why their research is so interesting. These are investigations that they’ll sometimes be doing for decades. Perhaps a few of them do it simply because it’s a job. But I think, for the most part, scientists are doing this work because they themselves have this intense passion and because they themselves find these things marvelous. You can sometimes find a way to frame your own story just by understanding the scientists’ passion for the subject.

Johnson: When mapping out a book or feature article how much attention do you pay to the structure? Do you have a system for organizing the flow of ideas or do you rely largely on what feels right?

Zimmer: I try to see the story in my head. I approach stories visually, I’m not sure why. If it’s too big to see it all in my head I will get out a piece of paper and draw a bunch of boxes with arrows and so on. Because you have to have the structure. One of the reasons that’s important is it prevents you from making the story too tangled up and complex. I teach a class at Yale and when I’m teaching students I often find myself saying to one of them, “You’re making the story too complicated. What is the one really important point that you want us to understand and how are you going to get us there?” Mapping out a story, either mentally or on a piece of paper, is incredibly important for getting that structure right.

Carl Zimmer and David Dobbs discuss their craft, ScienceOnline2011 / Ryan Somma, Flickr

Johnson: Who are some of the science writers working today that you think do this most effectively?

Zimmer: It depends on the genre. In books, for example, Rebecca Skloot and Joshua Foer have each come out with a book that does a fantastic job of mixing together hardcore science with personal experience in a way that is original and very compelling. [Editor's Note: See David Dobbs' piece "How Rebecca Skloot built The Immortal Life of Henrietta Lacks"]. In terms of magazine writers, I mentioned Burkhard Bilger and David Quammen. I’ve also been impressed with a guy named John Colapinto who also writes for The New Yorker. He did a piece on this linguist in Brazil called “The Interpreter” that I thought was fantastic. It was so deeply reported and so sweeping in exploring a scientist’s whole life, including his science. I was very impressed by that. There are also bloggers who are doing so many interesting things out there. I’ve read Ed Yong’s stuff from close to when he started and have watched him develop his own personal genre at his blog Not Exactly Rocket Science. In the very best sense he’s been making up the rules as he goes along. He’s got an approach that’s all his own.

Johnson: You’re a strong advocate of incorporating history into your science writing. My favorite book of yours, perhaps one of my favorite popular science books of all time, is Soul Made Flesh about the origins of neuroscience in 17th century England. But most of your writing focuses on contemporary research. What does the history of science offer when writing about the biology of fireflies or the viruses that kill thousands of people every year?

Zimmer: I think there a couple of good things that come out of utilizing history when you’re writing about new science. One is that, if you explore history it can make journalism more exciting. You can show how the work that people are doing today is helping to address questions that people have been struggling with for decades or even centuries.

One good example of this is the sequencing of the Neanderthal genome. It’s pretty cool when you read about what people have done in the last couple of years by putting together a genome based on ancient DNA extracted from fossils. But it’s much more profound when you look back at the 150 years or so of research about Neanderthals. When these fossils came out of the ground people were struggling desperately just to make sense of what they were. Were they human beings? Were they some other species? Were they our ancestors? Could they talk? Did we humans kill them off? Now we have an entirely new way of addressing those questions. Understanding this history just makes it so much more exciting and more profound.

The other way that history can be useful is that it can make you as a journalist more skeptical about the importance of new results. The fact is that people will come out with an experiment and then send you a press release announcing that it’s the greatest thing ever. But, if you know your history, you’ll realize that scientists knew this thirty years ago and that this latest experiment is just rehashing old results but with new technology. I think that the more journalists know about the history of science the better.

Jad Abumrad and Robert Krulwich discuss their award-winning RadioLab in New York / Pete Jelliffe 2006, Flickr

Johnson: As a writer who is constantly entering into new fields, where are you going to push yourself next?

Zimmer: One of the things I like is to get involved in projects where the medium seems very different from what I’ve been dealing with before. For example, I’ve been working with Jad Abumrad and Robert Krulwich at the radio show RadioLab and it’s just been fantastic. The way they turn science into sound and find a way to work within their medium is astounding. Twitter may limit you to 140 characters, but radio limits you to just your ears. You have to figure out how to work within these constraints and turn them to your advantage.

The weirdest experience I had was when I spent one long afternoon talking with Jad and Robert about the evolution of the eye. I was explaining all the new research on how eyes evolved on a molecular level. It’s truly amazing research. Then they took that, teamed up with the dance company Pilobolus, and incorporated it into a live performance. I was able to see the show in Berkeley recently. I was literally watching dancers on stage playing the part of photoreceptors in the retina, and they got it right. It was great! They managed to get across the molecular biology quite well. Afterwards, I was talking with one of the dancers and he was excited about how they could do more dances based on science. There are so many different ways of doing this job. It’s a very exciting time to be communicating science.

Click here for Part Two: Carl Zimmer Delves Beneath the Surface of Science Writing

Previous Interviews at The Primate Diaries:

• Frans de Waal on Political Apes and Building a Cooperative Society
• Lee Alan Dugatkin on Peter Kropotkin, Anarchism, and Cooperation in Nature

"Mental Health" by Nathaniel Gold

Imagine that you’re in a room with 100 psychopaths. The first thing you’ll probably want to do is leave that room. However, once you do, you discover a booth installed with one-way glass where you can watch what’s taking place without anyone seeing you. Comfortably seated, you observe a strange experiment taking place. A few of the individuals have on white coats and are carrying around clipboards while most are being run through a battery of psychological tests.

Slowly the frantic activity begins to make sense. Some test subjects are looking at video monitors and have sensors attached that measure their galvanic skin response to the images they see. Others are being given questionnaires to elicit their answers to a variety of social situations. Still others are being placed inside an fMRI scanner to measure the blood flow in different regions of their brains. All of these are standard methods in the psychological and brain sciences. But what’s most striking to you is the fact that this study is being conducted on psychopaths by psychopaths.

“Subjects reported a consistent disregard for the feelings of others and a lack of remorse in cases where they’ve hurt someone,” reported one researcher from his report based on answers from the questionnaire.

“This is consistent with the fMRI results that show significantly less blood flow to the paralimbic system, especially those regions involving emotion,” adds another looking at her analysis of the brain scan data.

“The skin conductance data also agree, showing little or no emotional reaction to violent or disturbing imagery,” reports a third who seems to be the one in charge of this strange experiment.

“These results suggest that the human species is inherently deceitful, antisocial, and has little regard for others,” he says. “Evolution has honed us to be selfish actors interested only in maximizing our individual potential at the expense of everyone else.” The other researchers nod in agreement, for that is certainly what the results show.

From where you sit it’s clear that something is terribly wrong with this study. Because they were only testing psychopaths the researchers’ data may be consistent but it’s only applicable for that one group. However, because the researchers were also part of that group and saw the world in the same way, they made the false assumption that humans everywhere behaved that way too. This is known in the sciences as confirmation bias, preferring conclusions that support someone’s own personal preferences or outlook even when the evidence is weak to nonexistent. This usually happens unconsciously. It’s the tendency we all have to prefer interpretations that support our preexisting beliefs. This is why scientific studies try to get a large and diverse sample size to draw their conclusions from.

Obviously the above example could never happen in real life, but it represents a simplified thought experiment to address a larger question about how research on human cognitive evolution is carried out. What happens if researchers inadvertently fall prey to confirmation bias at a societal level? Would the same false results that affected the hypothetical psychopath study also affect other assumptions about human nature?

Addressing this question psychologists Joseph Henrich, Steven J. Heine and Ara Norenzayan at the University of British Columbia (where I am also located) published a paper last year in the journal Behavioral Brain Sciences. Their research documents how most of the studies that psychologists claim show human universals are really just extrapolations from a single social group, the cultural equivalent of the psychopaths in my example. As The New York Times wrote in their review:

According to the study, 68 percent of research subjects in a sample of hundreds of studies in leading psychology journals came from the United States, and 96 percent from Western industrialized nations. Of the American subjects, 67 percent were undergraduates studying psychology — making a randomly selected American undergraduate 4,000 times likelier to be a subject than a random non-Westerner.

The subpopulation that Henrich and colleagues found to be overrepresented are entirely WEIRD (Western, Educated, Industrialized, Rich, and Democratic) societies. While it’s bad enough that WEIRD American undergraduates are serving as our model for human behavior, what their paper goes on to document should be of concern to all behavioral and cognitive researchers (particularly those whose work focuses on human evolutionary explanations).

When these affluent American and non-Western populations are compared there are important differences in domains as seemingly unrelated as visual perception, fairness, cooperation, spatial reasoning, moral reasoning, reasoning styles, and even the heritability of IQ. In all cases American undergraduates didn’t simply differ, they differed substantially. Nevertheless, they form the basis of most researchers’ assumptions about human nature even though, as Henrich and colleagues conclude, “this particular subpopulation is highly unrepresentative of the species.”

To highlight one domain in which American undergraduates differ from most other populations in the world consider a neutral category like visual perception. Looking at the figure below, which horizontal line, “a” or “b”, would you estimate is longer?

If you chose “b” than you are in line with a substantial number of Americans (both undergraduates and children) who chose the same one. In fact, both lines are identical in length. This has become known as the Müller-Lyer Illusion, named after the German psychiatrist Franz Carl Müller-Lyer who first discovered it in 1889. However, if you show the same two lines to people in many non-Western societies (particularly hunter-gatherer societies) they will be more likely to identify the two lines as identical. In a series of cross-cultural experiments in 1966 psychologist Marshall H. Segall manipulated the length of line “a” until it reached the point where respondents reported that the two were identical in length. The results of these experiments can be seen in the graph below.

The strength of the Müller-Lyer Illusion in 16 separate societies. Reproduced from Henrich et al. (2010)

The vertical column represents the Point of Subjective Equality (PSE), or how long line “a” had to be before respondents said they were the same length. In other words, PSE is a measure of how effective the illusion is for different populations. As the graph indicates, Americans (labeled as “Evanston” for where Segall tested undergraduates at Northwestern University in Illinois) were the population most fooled by this illusion and required line “a” to be an average of one-fifth longer than line “b” for both to be perceived as equal. They were followed by white South Africans from Johannesburg. In contrast, the San foragers of the Kalahari were not affected by the illusion while most other societies in the study were only marginally affected.

Why would Americans be so susceptible to this illusion? Our environment. Most Americans are raised in a society where horizontal lines and sharp corners make up much of modern architecture. The brains of American children (and, presumably, most children in highly industrialized countries) have adapted to make optical calibrations as a result of their unique environment. The San and many other small-scale forager or horticultural societies don’t grow up in a manufactured environment so their brains are unaffected by such illusions.

A similar difference can be found in what psychologists call “folkbiological reasoning.” Cognitive scientists testing children drawn from U.S. urban centers (where most universities are located) have developed an influential developmental theory suggesting that there is a cognitive shift that takes place between ages 7 and 10. As Henrich and colleagues state in their paper:

Before age 7, urban children reason about biological phenomena by analogy to, and by extension from, humans. Between ages 7 and 10, urban children undergo a conceptual shift to the adult pattern of viewing humans as one animal among many.

This shift has been considered a process that all human children go through. The problem with this reasoning, Henrich points out, is that it only applies to one subset of children: those who live in urban environments. Similar cognitive tests of children in Native American communities in Wisconsin and among the Yukatek Maya communities in Mexico showed none of the empirical patterns that the American urban children displayed. The answer, of course, is that urban children grow up in an impoverished environment where they will rarely, if ever, interact with animals other than humans (with the occasional dog or cat kept as a pet). This is a very different environment from many non-Western societies, and certainly from the one our remote ancestors lived in.

As a result, the “unnatural” environment of these WEIRD children resulted in anthropocentric assumptions about the natural world until they were taught differently by teachers or from television (though I often wonder how an increased exposure to nature when they’re young might influence adult attitudes about the importance of environmental issues). Given this, as Henrich points out, it makes as much sense to use urban children in studies of human cognition as it would to study “normal” physical growth in malnourished children. Because the psychologists who carried out these studies likely grew up in an urban environment themselves (rural students are significantly less likely to attend graduate school, particularly at top-ranking institutions) the confirmation bias of such studies are perpetuated. It’s almost as if psychopaths were conducting research on themselves and claiming their results were universal.

Of course, there is one important difference between psychopaths and American society. Psychopathy, and Anti-Social Personality Disorder more generally, is a diagnosed mental disorder that has a partial basis in genetics, not just the environment. Nevertheless, the confirmation bias that exists in many psychological studies represents a distortion of reality that has just as much potential to be passed on to subsequent generations.

The fact that empirical differences exist on identical psychological studies when replicated cross-culturally should make evolutionary researchers take caution (especially Evolutionary Psychologists who are most guilty of essentializing these studies). What Henrich and colleagues have called for is a renewed effort to conduct similar cross-cultural research before making grand claims about the species as a whole. At the very least it means that researchers and science journalists alike should be careful not to perpetuate ideas that appeal to their own beliefs but which may have no basis in other societies. To do otherwise would be to confuse our own reflection in a hall of mirrors with a crowd of people making identical movements. That would clearly be psychotic.

This post originally appeared at the Public Library of Science (PLoS) Blogs.

Reference:

Henrich, J., Heine, S., & Norenzayan, A. (2010). The weirdest people in the world? Behavioral and Brain Sciences, 33 (2-3), 61-83 DOI: 10.1017/S0140525X0999152X

   "The Social Network" by Nathaniel Gold

Let’s face it, as a species we’re obsessed with ourselves. The vast majority of us spend our days at work or school where a considerable amount of time is taken up not discussing the important issues of the day, but rather the juicy details of one another’s personal lives. Then we go home only to sign on to social network services like Facebook, Twitter, or Google+ and continue where we left off. In this respect we’re fairly typical primates. Most of our simian relatives, particularly our great ape cousins the chimpanzees and bonobos, like nothing better than keeping a watchful eye on what other members of their troop are up to. But our species has taken this preoccupation one step further.

Human beings are the most social of the primates and have the largest group sizes of any species in our order. For about 90% of our existence we lived in hunter-gatherer societies with populations that likely clustered around 150-200 individuals. By way of comparison, baboons come in a distant second with an average of about 50 group members. Now, thanks to modern industrial agriculture, our species has pushed that range well into the millions, a development that has resulted in considerable stress on our slightly above average primate brains. Of course, all organisms need to successfully predict and navigate their environments in order to relay their genes on to the next generation. It’s just that this becomes increasingly complicated when there are many individuals all interacting in the same environment simultaneously. Merely keeping track of these relationships requires a considerable amount of time and energy, not to mention brain power.

In the 1990s the British evolutionary anthropologist Robin Dunbar championed an idea known as the Social Brain Hypothesis. He found that mammals who lived in the largest social groups often had the largest neocortex to brain ratio. Since the neocortex — composed chiefly of gray matter that forms the outermost “rind” of our cantaloupe-sized stuff of thought — is associated with sensory perception and abstract reasoning, Dunbar hypothesized that the demands of group living resulted in a selection pressure that promoted the expansion of neocortical growth.

In 2009 I co-authored a study in the Journal of Human Evolution with colleagues Evan MacLean, Nancy Barrickman, and Christine Wall of Duke University that found no relationship between relative brain size and group size in lemurs (a clade of strepsirrhine primates that last shared a common ancestor with the haplorhine monkeys and apes about 75 million years ago). However, where it comes to these more recently evolved haplorhines, the data is remarkably consistent with Dunbar’s interpretation (see Figure 1 below).

Figure 1. As average group size increases in monkeys and apes, so does neocortex ratio. Reproduced from Dunbar and Shultz (2007).

Primates, and humans in particular, are such good social cooperators because we can empathize with others and coordinate our activities to build consensus. It is what also makes us so remarkably deceitful, allowing us to manipulate other members of our group by intentionally making them think we will behave one way when our actual plans are quite different. A successful primate is therefore one who can keep track of these subtle details in behavior and anticipate their potential outcome.

But therein lies a chicken-and-egg problem. How do we know whether it’s the social networks that have promoted an increase in neocortical growth or whether that same expansion of gray matter simply allowed these social networks to expand? A new study published in the November 4th edition of Science addressed this question by housing monkeys in different sized groups to find out if their neocortical gray matter increased as the number of individuals grew. A team of neuroscientists led by Jérôme Sallet and Matthew Rushworth of the University of Oxford in England randomly assigned 34 rhesus macaques to separate social groups ranging in size from 1 to 7. The researchers conducted magnetic resonance imaging (MRI) scans on 23 of the monkey’s brain structures both before they were placed into their various groups and again after more than a year had passed.

Their analysis revealed a clear, linear relationship between the size of a monkey’s social network and an increase of neocortical gray matter in regions involved with social cognition (such as the mid-superior temporal sulcus, rostral prefrontal cortex as well as the frontal and temporal cortex). Previous research has shown that these regions are important for a variety of social behaviors, such as interpreting facial expressions or physical gestures, “theory of mind,” and predicting the behavior of other group members. Overall the monkeys demonstrated an expansion of gray matter ranging from 3-8% (depending on the brain region) for each additional member of their social network. In other words, monkeys that lived in the most socially complex group had an average increase of 20% more neocortical growth than monkeys housed individually.

Figure 2. Gray matter increased with social network size; P < 0.005. Reproduced from Sallet et al. (2011).

In order to make sure that the increased brain growth corresponded with more successful social behaviors, the research team also tested whether there was a correlation between gray matter volume and a monkey’’s rank within their group (as in many other primates, rank in rhesus macaques is a strong predictor of reproductive success). Once again the researchers found a linear relationship, at a ratio of 3-to-1, between a monkey’s dominance behavior and the growth of key regions in their neocortex. This means there was individual (potentially genetic) variation that allowed certain monkeys to experience greater neocortical growth than other group members that were living in an identical environment. This strongly suggests that it is the cognitive demands of a larger social network that has resulted in the growth of brain regions beneficial to social behavior in primates.

“Social network size, therefore, contributes to changes both in brain structure and function,” said Sallet. “Individual variation in brain anatomy should have implications for an individual’s success within the social group.” Crucially, these individual differences remained consistent for more than four months. Certain individuals happened to be better suited for dealing with the demands of larger social groups, but they had to first live in that environment before their natural abilities could emerge.

This raises a provocative question. Individual variation is the raw material on which natural selection operates. But in a rapidly changing environment — like in many human societies ever since the invention of agriculture 10,000 years ago — there will be many new adaptive opportunities that may never have existed throughout most of human evolution. Consider those individuals who have made successful careers (and had large families) through their skill as novelists, DJs, or computer programmers. Certain aspects of their skill sets would certainly have been based in our long history of hominin evolution, but other parts may have had little or no adaptive value at any other time than the present.

It is this capacity that was the focus of a study published last month in Proceedings of the Royal Society that investigated the biological variability in another form of social behavior: online social networking. In a collaboration between neuroscientists and anthropologists led by Ryota Kanai and Geraint Rees from the Institute of Cognitive Neuroscience at University College London, the researchers investigated social media users, specifically Facebook, for the same kinds of biological variation that distinguished certain social monkeys over others.

“These services allow individuals to articulate and make visible their friendship networks,” explained Kanai, “and it is apparent that there is considerable variability in the size of such networks.”

By comparing the differences between individuals and the size of their online network of friends, real-world friends, as well as the size of neocortical brain regions involved in social behavior, the researchers were able to identify a strong correlation between the volume of three neocortical regions and the number of that individual’s Facebook friends. Crucially, these brain regions (the right superior temporal sulcus, left middle temporal gyrus, and entorhinal cortex, areas previously implicated in social perception and associative memory) had no relationship to the real-world social networks of these individuals. There was only one area, the amygdala, that showed a correlation between gray matter density and both forms of social networking. The other brain regions seemed to be, quite literally, wired for the web.

However, unlike the study with monkey social networks, there was no way to determine whether it was the number of an individual’s Facebook friends that had pushed this neocortical growth or if it was actually the other way around. But given the similarities in function, it is certainly a tempting conclusion to reach. Could it be that online technology has allowed some individuals to express (and expand) a form of social behavior that emerged for other adaptive reasons but which has been underutilized until now?

Given the regular jeremiads from self-appointed cultural guardians over what they see as the danger of our increasing reliance on online networks at the expense of real-world ones, the possibility that we may actually be enhancing untapped potential is a refreshing idea. At the same time, however, it’s probably a good idea to wait until we know for sure before sharing the news with any other primates. The last thing I need is a slew of hairy faces crowding my wall. I have enough trouble keeping track of my online network of friends as it is.

References:

Sallet, J., Mars, R., Noonan, M., Andersson, J., O’Reilly, J., Jbabdi, S., Croxson, P., Jenkinson, M., Miller, K., & Rushworth, M. (2011). Social Network Size Affects Neural Circuits in Macaques, Science 334 (6056), 697-700. DOI: 10.1126/science.1210027

Kanai, R., Bahrami, B., Roylance, R. and Rees, G. (2011). Online Social Network Size is Reflected in Human Brain Structure, Proceedings of the Royal Society B: Biological Sciences, published online Oct. 12, 2011. DOI: 10.1098/rspb.2011.1959

Dunbar, R.I.M. and Shultz, S. (2007). Evolution in the Social Brain, Science 317 (5843), 1344-1347. DOI: 10.1126/science.1145463

MacLean, E.L., Barrickman, N.L., Johnson, E.M. and Wall, C.E. (2009). Sociality, Ecology, and Relative Brain Size in Lemurs, Journal of Human Evolution 56 (5), 471-478. DOI: 10.1016/j.jhevol.2008.12.005

        "Stalin" by Nathaniel Gold

The anti-Darwin industry among fundamentalist Christians has produced thousands of pages of misinformation in their attempt to tar and feather the theory of evolution. I have responded to many of these false claims previously. However, one assertion that is especially outlandish is that the Soviet dictator Joseph Stalin was a devoted Darwinian who funded a program to create “ape-man Superwarriors” in his goal for world domination. As Creation Ministries, publisher of the Journal of Creation and advocate of a young Earth literal interpretation of the Bible, insisted in 2006:

Soviet dictator Joseph Stalin wanted to rebuild the Red Army, in the mid-1920s, with Planet-of-the-Apes-style troops by crossing humans with apes. . . Stalin is said to have told Ivanov, ‘I want a new invincible human being, insensitive to pain, resistant and indifferent about the quality of food they eat.’

Their only legitimate source for the claim comes from a 2002 paper in the academic journal Science in Context, by the Russian historian of science Kirill Rossiianov. Rossiianov’s study follows the ill-fated attempt by the Russian physiologist Il’ya Ivanov to cross-breed humans with anthropoid apes. His research offers an important warning about the ethical abuses that can occur when proper standards are not enforced, but Rossiianov’s paper clearly demonstrates that creating “superwarriors” had no part in Ivanov’s work. The alleged quote from Stalin is not found in the paper and there is no evidence that Stalin ever made such a statement. It should come as no surprise, therefore, that Creation Ministries’ assertion has absolutely no foundation.

However, why the Soviets would fund such a human-chimp hybridization program in the first place and what can be learned from this sordid tale of ethical misconduct is an important topic and fascinating in its own right. Ivanov represents a scientist, widely respected in his field, whose dedication to find out if something could be done blinded him to ask whether it should be done. It also reminds us of the role that politics can play in the development of scientific research even if the scientists directly involved are not political themselves.

Contrary to the claims of conservative Christians, Il’ya Ivanov’s interest in hybridization occurred long before the Russian revolution of 1917 and had little connection with Marxist ideology. Following his graduation in 1896 with the equivalent of a PhD in physiology, Ivanov conducted research in bacteriology at the Institut Pasteur in Paris before working with the world famous physiologist Ivan Pavlov. Ivanov utilized the same surgical techniques that earned Pavlov a Nobel Prize and was successfully able to extract animal sex glands so as to develop techniques of artificial insemination in purebred horses. This research was subsequently expanded to farm animals more generally and Ivanov became the leading international figure in the study of artificial insemination.

Ivanov’s first mention of his idea for using artificial insemination to determine if a human-ape hybrid could be produced occurred at an Austrian zoology conference in 1910. There is no indication that he had any plans to carry out such research at this time. However, seven years after the revolution, in 1924, Ivanov was conducting experiments on sperm disinfection at the Institut Pasteur when he was offered the institute’s support for his hybridization scheme:

They offered Ivanov free access to animals at the institute’s recently organized chimpanzee facility in the village of Kindia, French Guinea, but could not pay for other operational and travel expenses of the project.

After several failed attempts to secure funding, Ivanov eventually received $10,000 from the Soviet Financial Commission and his project was subsequently approved by the Soviet Academy of Sciences (Ivan Pavlov was a distinguished member of the Academy and was present the day this decision was made). It was certainly Ivanov’s distinguished reputation that allowed the project to move forward. In his proposal to the Academy he stated that he wanted to test various hypotheses that had been suggested in the scientific literature.

One such hypothesis was that of the German scientist Hans Friedenthal whose analysis of blood cells in 1900 between chimpanzees, gorillas, orangutans, and humans showed that they were serologically far more similar than had previously been expected. As a result, Friedenthal proposed that anthropoid reproductive cells could be similar enough to result in a hybrid between humans and other apes. In the following two decades other researchers, such as the Dutch zoologist Hermann Marie Bernelot Moens and the German sexologist Hermann Rohleder, sought to test this prediction by inseminating chimpanzee females with human sperm. However, their attempts never got beyond the planning stage and, in the case of Moens, his research plans resulted in him being fired from his teaching position.

With his small budget and use of Institut Pasteur’s facility Ivanov and his son traveled to French Guinea in Western Africa to carry out his artificial insemination experiments in March, 1926. However, his research was hounded at every turn. The “research station” had only two veterinarians on staff and Ivanov’s presence resulted in outrage that he might report on the atrocious conditions:

Ivanov explained that the hostility of the station’s staff arose from their fears that he would report back to Paris about the real problems at the facility. According to the documentation that he managed to see, about seven hundred chimpanzees had been bought from native hunters since the founding of the station in 1923, and more than half of them had died before they could be shipped to Paris for biomedical experiments.

Local hunters had kidnapped the chimpanzees from the wild as infants and all were still juveniles when Ivanov arrived. He only attempted to inseminate three females before being forced to abandon the project as useless. Desperate to make use of his limited funding, Ivanov then made the horrific decision to attempt the insemination of African women with chimpanzee sperm without their knowledge. He made a proposal to doctors at a local hospital about his experiment and was ready to proceed when the General Governor of French Guinea, Paul Poiret, rejected the plan. Out of options and funding, Ivanov and his son decided to return home. By the time the two boarded their ship they had been in Africa for just over one month.

Ivanov hoped to pursue his experiment again in Russia through the use of women volunteers (and he found at least one who was willing to participate). However, when word got out that Ivanov had attempted to inseminate African women without their consent he was condemned by the Soviet Academy of Sciences and all support was eliminated. An investigation concluded that Ivanov’s behavior:

[M]ight undermine the trust of Africans in European researchers and doctors and make problematic any further expeditions of Russian scientists to Africa. Thereafter, the Academy did not want to deal with Ivanov and deprived him of any further support.

While some of his previous support was based in the political ideology at the time, there were strong political divisions that split scientific opinion on a range of issues and Ivanov was caught in between. To some Marxists it was hoped that a program of positive eugenics could lead to an improvement in the population similar to Marx’s description of historical materialism. Researchers in this camp, such as Herman Muller, hoped to use “scientific” techniques so parents thought to have a good genetic background would have more children, a policy in sharp contrast to the negative eugenics later employed by the Nazis that emphasized sterilization. Muller and other geneticists hoped that Ivanov’s research could lead to a better understanding of what qualities to look for. However, other scientists rejected genetic research as bourgeois or imperialist and advocated the inheritance of acquired characteristics (what is commonly known as Lamarckism). It was these researchers, led by the charismatic biologist Trofim Lysenko, who had Stalin’s support at the time.

Lysenko rejected genetic inheritance and advocated Lamarckian acquired characteristics. Image from Soyfer, V. N. The State and Science (Hermitage, New Jersey, 1989), Wikimedia Commons

In a telling example of the political divisions Ivanov became caught up in, Cambridge historian Martin Richards describes how Muller, one of Ivanov’s supporters, sent a letter to Stalin advocating a positive eugenic program. However, the timing couldn’t have been worse. Lysenko and his followers had warned Stalin that genetic research would lead to eugenics as well as fascism and, now, Stalin was convinced. Muller was forced to flee Moscow for fear of being arrested and, days later, received word that several of his colleagues were shot as “enemies of the people.”

It was in this atmosphere that Il’ya Ivanov met his end. After several additional attempts to receive support for his research without success, Ivanov was caught up in the ideological battle. One of his scientific enemies, Orest Neyman, accused him of “sabotage” because some of his artificial insemination farm instruments had apparently malfunctioned. On December 13, 1930 Ivanov was arrested by the secret police and convicted of “having created a counterrevolutionary organization among agricultural specialists” and banished to Kazakhstan where he died two years later. His main accuser took over Ivanov’s position as head of the laboratory.

This history raises a number of troubling issues. The fact of the matter is that Il’ya Ivanov cannot simply be dismissed as a rogue ideologue abusing science for dubious political purposes. Rather, he was an internationally respected leader in reproductive physiology and the foremost expert at the time on the artificial insemination of farm animals. His human-chimp hybridization experiments came out of collaboration with other respected scientists and with the direct assistance of the Institut Pasteur, one of the leading scientific institutions in the world at the time. Furthermore, while there was apparently no overt racism in his research, his decision to inseminate African women without their knowledge or consent can only be understood in the context of a racist and sexist colonial attitude.

While Ivanov doesn’t seem to have had a political motivation for his research, some of those involved in supporting his work certainly did. In this way Ivanov’s experiment was only made possible because of a network of individuals and institutions with specific political ambitions even though Ivanov himself wasn’t directly involved in them. When we consider scientific experimentation today, where do we draw the line between sound research and ethical violation? In what ways are funding decisions based on political considerations unrelated to the direct question a researcher hopes to answer? How does state power influence scientific research, and what relationship do scientists have with those on the receiving end of this power? Even though no one, other than the scientists involved, were ever hurt by this cross-breeding research it nevertheless raises serious concerns. While the question of the “ape-man superwarriors” myth can easily be discarded after examining this history, other questions are not as easy to dismiss.

References:

Rossiianov, K. (2003). Beyond Species: Il’ya Ivanov and His Experiments on Cross-Breeding Humans with Anthropoid Apes, Science in Context, 15 (02). DOI: 10.1017/S0269889702000455

Richards, M. (2008). Artificial insemination and eugenics: celibate motherhood, eutelegenesis and germinal choice, Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, 39 (2), 211-221. DOI: 10.1016/j.shpsc.2008.03.005

    "Nosferatu" by Nathaniel Gold

Medveđa, Serbia. Jan. 1732 — The Carpathian mountains loomed ominously to the east, as if nature herself was conspiring with evil. In the valley below a shadow had been draped over the corpses that now littered the quiet cemetery. Of the forty villagers exhumed that morning, a total of thirteen had been identified as vampires. Fresh blood seeped from their mouth, nose, or the gaping wounds in their chest where the stake had been pounded in. The gore was clear evidence of their demonic guilt.

Dr. Johannes Flückinger, regiment medical officer dispatched by the Honorable Supreme Command, surveyed the ghastly scene. He was clearly uneasy about being sent to this small village on the remote edge of the Habsburg Empire. His disgust for the local haiduks was evident as he gazed upon a newborn child, who, “because of a careless burial had been half eaten by dogs.”

The young doctor hunched over what had once been the child’s mother, a 20-year-old peasant woman named Stana, and proceeded with his dissection. He noted that she was “quite complete and undecayed” despite having died in childbirth two months earlier. Like the others, her blood had not coagulated and after prying open her rib cage he documented that her lungs, liver, and spleen were all still fresh. The woman’s skin was described as “fresh and vivid” and she had a pool of extravascular blood in her stomach and chest cavity. The only interpretation could be that, after being turned into a vampire, she had risen from her grave to feast on the blood of the living.

“After the examination had taken place,” Flückinger wrote in his official report, “the heads of the vampires were cut off by the local gypsies and then burned along with the bodies, and then the ashes were thrown into the river Morava.”

The first to be transformed, Flückinger learned from the Serbian villagers, was a former soldier by the name of Arnod Paole who had fled his post in Turkey after being “troubled” by a vampire there. However, after settling in the village and being betrothed to his neighbor’s daughter, Paole met with a sudden and unexpected death. Not long after, people began to report seeing Paole wandering through the village after night-fall. Some swore that he had even attacked them or that he was observed taking the shape of a black dog, as though hunting for prey. More than twenty people had mysteriously died in the village since Paole met his untimely end, and most within a few months of each other.

“Paole attacked not only the people,” Flückinger reported, “but also the cattle, and sucked out their blood.” These were the two ways by which vampirism had then spread throughout Medveđa: some were bitten directly while others had eaten the infected meat and become vampires as well. Apparently, once they were turned, vampires not only behaved as though possessed by wild beasts, they could also adopt a beastly shape, or transmit their vampirism through animals to an unsuspecting human victim. In order to end Arnod Paole’s reign of terror, the villagers of Medveđa “drove a stake through his heart, according to their custom, whereby he gave an audible groan and bled copiously.”

Vampires were almost entirely unknown to the European imagination prior to 1730 and Johannes Flückinger’s strange report would become known as the most thoroughly documented–as well as the most widely circulated–vampire narrative in the world. Following the Treaty of Passarowitz in 1718, much of the region now known as the Balkans was ceded to the Habsburg Monarchy by the Ottoman Empire. Along with it came a rich folkloric tradition which quickly merged with European ideas of witchcraft that had gripped the continent for the past three centuries. These stories would be widely reproduced in French, German and, later, in English, to eventually find their way into the hands of an obscure Irish writer and theater manager by the name of Bram Stoker.

The storyline of Stoker’s 1897 novel Dracula about a Transylvanian Count and his invasion of English virtue would be almost entirely original. However, key attributes of the vampire itself would draw directly from Slavic folklore, particularly where there was an overlap with European witchcraft. While Bram Stoker’s Dracula was an elegant and seductive aristocrat, the Slavic vampires were typically rural villagers that had become possessed. In appearance and mannerism they would have shared more in common with Max Schreck’s animalistic performance in the German silent classic Nosferatu than with Bela Lugosi’s theatrical mesmerism as the Hungarian Count. However, the depiction of the vampire as a savage beast of prey, the infection of new vampires through bites or contaminated blood, their ability to transform into specific animal “familiars” (especially wolves and bats), and the method of dispatching the undead by murdering them in their coffins while they slept, would all be borrowed directly from Slavic folklore.

What the Slavic and European vampire mythologies both have in common however is that they tell an important story about how people understood natural events such as death, decomposition, and the transmission of disease prior to the advent of scientific medicine. They also serve as an illustration of the anxiety present in many Christian societies over the delicate line that seemed to separate human from animal.

“Far from being merely fanciful horror stories,” writes UCLA historian Paul Barber in the Journal of Folklore Research, “the vampire stories prove to be an ingenious and elaborate folk-hypothesis that seeks to explain otherwise puzzling phenomena associated with death and decomposition.” In nearly all cases, individuals would be identified as vampires after they were exhumed and irregularities found with the condition of their bodies. The most common reasons were lack of decomposition or because liquid blood was found around their mouth and nose.

Decomposition is largely misunderstood even today and is not the rapid or complete process commonly assumed. As Barber notes, putrefaction begins at about 50°F and occurs most rapidly at temperatures ranging between 70° and 100°. However, the temperature even just a few feet below ground is usually much lower and decomposition occurs on average eight times more slowly than on the surface. In the case of the Medveđa village cemetery, it would therefore be unsurprising for bodies that were exhumed in January (with average surface temperatures at just above freezing) to remain relatively intact for weeks or even months.

Furthermore, because the bacteria that cause decomposition feed on the protein-rich content of the blood, if there had been significant haemorrhage (as would occur in a violent death or sudden accident) the process would be significantly slower. This fact may have only reinforced these folk traditions, since it would be expected that violent or rapid deaths were somehow unnatural to begin with. However, the most common way that vampires were identified was when liquid blood was seen around the corpse’s mouth, nose, or ears. It was commonly believed that vampires would so gorge themselves on blood that it would leak out after they’d returned to their grave.

“[Vampires] suck the blood of living people and animals in such great abundance,” stated one early Slavic account, “that sometimes it comes out of their mouths, their noses, and especially, their ears, and that sometimes the body swims in its blood which has spilled out into its coffin.”

What is more likely, Barber argues, is that local populations simply filled the gaps in their knowledge about the process of decomposition with folktales that could explain what they had observed. In actuality, during the normal process of decomposition the lungs become loaded with a dark red sanguinous fluid and the brain liquifies. Depending on the orientation of the body, this liquid would have leaked out as it was acted on by the pull of gravity. Ironically, individuals suspected of being vampires at the time of burial would usually be placed face down to make it harder for them to find their way to the surface. When these individuals were later exhumed, the red fluid in and around their mouth or nose would only confirm the original assumption. Add to this the eruption of sanguinous fluid when a stake is hammered into their lungs (an event that can emit sounds from a low groan to a high pitched scream as gases are forced outwards) and the misinterpretation would be complete.

In addition to flawed assumptions regarding death and decomposition, certain diseases (particularly ones that result in extreme psychological and behavioral changes) would only add to folk-hypotheses seeking to explain such unusual events. While both schizophrenia and tuberculosis have been proposed as potential natural influences on the folk tradition of vampirism, a study published in the journal Neurology by Juan Gomez-Alonso of the Servicio de Neurologia, Hospital Xeral in Vigo, Spain argues that many of the primary attributes of vampires show remarkable similarities to the physical symptoms associated with rabies.

“In certain cases, rabies appears similar to vampirism,” says Gomez-Alonso, “The rabid patient rushes at those who approach him, biting and tearing them as if he was a wild beast.” In both cases, the method of transmission is identical since rabies infections are caused through animal bites or blood to blood contact. While dogs are the most common animal associated with rabies today, rural villagers have historically had much greater interaction with wolves and these animals were a significant threat both to themselves and their livestock. There have also been many documented cases of rabies infection from bats both in Europe and the United States. “Consequently,” says Gomez-Alonso, “it would be imaginable that men and beasts with identical ferocious and bizarre behavior might have been seen, by a primitive witness, as similar malign beings.” It is notable that in the early Slavic accounts there was no distinction between vampires and what we would now call werewolves; in some versions a vampire was simply what a werewolf became after they died.

There are many additional characteristics that appear to connect vampirism and rabies. In terms of pathology, for example, humans that have contracted rabies typically die of suffocation or cardiorespiratory arrest. These types of deaths, according to Gomez-Alonso, result in post-mortem features consistent with those used to identify a vampire: blood is less likely to coagulate after death and hemorrhage is common, resulting in slower decomposition. Humans can also contract rabies by drinking unpasteurized milk or eating undercooked meat from a rabid cow (or through oral exposure to their blood or saliva during preparation). In this way, knowledge of how the rabies virus can spread might have been contained in these folk traditions, even if the actual mechanism remained mysterious.

Finally, Gomez-Alonso points out the historical coincidence that during the period when dramatic tales of vampires were first emerging from Eastern Europe, a major epidemic of rabies in dogs, wolves, and other wild animals was recorded in the same region between 1721-1728. This coincidence may have even been identified as early as 1733 when an anonymous physician argued that vampirism “is a contagious illness more or less of the same nature as that which comes from the bite of a rabid dog.” While it is likely that multiple natural factors would have influenced the folk tradition of vampirism, it is remarkable that rabies has the potential to connect such seemingly unrelated elements as transmission, behavior, and post-mortem pathology.

“Among the European peasantry wolves were dreaded because of the physical threat they represented,” says Jessica Wang, professor of history at University of British Columbia in Vancouver, Canada “but also because they could transmit the symptoms that we now understand are caused by the rabies virus.” Wang is currently engaged in research documenting the social history of rabies, in which she has identified the common theme of animal possession as a folk-hypothesis to explain the transfer of symptoms from animals to humans. “People associated witchcraft and occult forces with animals,” she says, “as well as the crossing of the line between animals and humans. I think a lot of the fear was based on the fact that humans are animals and what happens if people concede that line rather than try and preserve it.”

In one newspaper account Wang identified from Prussia in the nineteenth century, a farmer was “seized with rabies” only to run amok through the village as though possessed. “He finally took refuge in his own house,” she related, “where he attacked his wife, a young woman to whom he had recently been married. He literally tore her to pieces.” After committing the horrible deed he was then seized with another convulsion and inflicted wounds upon himself from which he died. When neighbors entered the house both dead bodies were found on the floor “frightfully mangled and still warm.” The newspaper account didn’t specify whether or not he had been buried face down.

Just as the vampire myth has its origin in historical events, the cultural tradition that gave rise to it may also have had a natural basis. While these early vampire stories share little with the modern myths about such creatures, the folk tradition that spawned them does contain many of the same inherent fears. “What happens when people do, in a sense, become animals and lose control of their physical bodies through the display of uncontrolled aggression?” Wang asks. “I think a lot of these rabies narratives reflected these kinds of fears. They’re ultimately about the line between animal and human and the ease with which it can be breached.”

References:

Barber, P. (1987). Forensic Pathology and the European Vampire, Journal of Folklore Research 24 (1), 1-32. URL: http://www.jstor.org/stable/3814375

Gómez-Alonso J. (1998). Rabies: a possible explanation for the vampire legend. Neurology, 51 (3), 856-9. PMID: 9748039

     "Tradition" by Nathaniel Gold

Culture defines who we are but few can explain where it comes from or why we adopt one tradition over another. In the classic musical The Fiddler on the Roof the family patriarch, Tevye, muses on this basic fact of human existence:

Here in Anatevka we have traditions for everything… how to eat, how to sleep, even, how to wear clothes. For instance, we always keep our heads covered and always wear a little prayer shawl… This shows our constant devotion to God. You may ask, how did this tradition start? I’ll tell you – I don’t know.

The origin of particular cultural traits in human populations has long been a mystery to anthropologists. Many societies have responded the same way Tevye did, “it’s merely part of our culture, what else do you need to know?” Nevertheless, the maintenance and dissemination of cultural traits remains a fascinating topic that scientists have long struggled to understand. More recently, however, researchers have discovered that humans aren’t unique in this regard. Nonhuman primates also have culture and research into how this is transmitted between individuals has recently taken a major step forward.

While nonhuman primates don’t have obvious cultural traditions the same way humans do, such as variation in their clothing or adding extra spice to their food, primatologists have nonetheless identified behavioral practices that vary between communities and which are transmitted through social learning. For a behavior to be considered a cultural practice in nonhuman primates it must meet certain conditions: the behavior must be practiced by multiple members of the community, it must vary between societies, and the potential for that same behavior must exist in other societies.

A good example of such a cultural trait was just discovered last year and published in the journal Current Biology (review here). Kibale Forest chimpanzees were found to use sticks to get at the honey in a fallen log, whereas Budongo Forest chimpanzees used chewed leaves as sponges to collect the same thing. Both societies had the same tools at their disposal, but they each chose a different approach. A single individual first used one of these techniques and other members of the group adopted it through imitation and social learning. This is merely the latest example of cultural traditions in different chimpanzee societies.

However, some societies have more unique cultural traits than others. To understand why this would be researchers Johan Lind and Patrik Lindenfors of the Centre for the Study of Cultural Evolution and the Department of Zoology at Stockholm University, Sweden analyzed the demographics of different chimpanzee societies in their paper published in the Public Library of Science. They hypothesized that, since infants so readily imitate their mothers as they’re growing up, the number of females within a given society may explain the number of cultural traits. Individuals spend at least eight years in close proximity with their mothers while fathers are scarcely involved. Furthermore, tool use is central in chimpanzee societies and females use tools more frequently than males do. Since chimpanzees are patrilocal (males remain in their natal group while females migrate at puberty) any cultural traits learned by young males would remain in the society while young females would transfer that same trait to nearby societies.

Because females express and transmit more culture than males, and because females transfer between communities bringing with them their cultural knowledge, the number of cultural traits present in any given chimpanzee community should depend on the number of females in that community. Thus, we hypothesize that the number of cultural traits in chimpanzee communities should correlate with the average number of females in chimpanzee communities, but not with the average number of males.

Figure 1. Female Group Size and Number of Cultural Traits. Reproduced from Lind and Lindenfors (2010).

As can be seen in Figure 1 above, the number of societies studied with documented cultural traits is not high (n = 7), however the researchers found a significant correlation between the number of females in a society and the number of cultural traits present (p = 0.010). There was no correlation between cultural traits and the number of males.

This implies that females are critical in chimpanzees for transmitting cultural traits and maintaining cultural diversity. The reported pattern may be explained by the fact that females transfer between communities, bringing with them novel cultural traits and consequently increasing the cultural diversity of the community as a whole.

This is not to say, of course, that there will always be a direct correspondence between the number of females and the number of cultural traits in that society (as can be seen by Mahale M-group), but the evidence is suggestive that there is a pattern of cultural transmission in chimpanzees being driven by females.

The authors point out that the pattern for human societies is different from chimpanzees and that the number of cultural traits increases as the population of both males and females increases. This would appear to demonstrate the important role that fathers play in the social learning of their children. However, as The Fiddler on the Roof reveals all too clearly, new cultural ideas from outside one’s community can infiltrate as societies continue to grow. Under such conditions neither mothers nor fathers can maintain a single cultural norm for long.

Reference:

Lind, J., & Lindenfors, P. (2010). The Number of Cultural Traits Is Correlated with Female Group Size but Not with Male Group Size in Chimpanzee Communities, PLoS ONE, 5 (3). DOI: 10.1371/journal.pone.0009241

Originally published at ScienceBlogs

      "Whistler's Grandmother" by Nathaniel Gold

Imagine you are on the Serengeti Plateau and your children are hungry. For miles in every direction there’s nothing but dry scrub grass with the occasional flat-topped acacia tree marking the landscape. Your oldest has found a spot to dig for tubers but he and your daughter aren’t strong enough to scrape away the hard, baked earth by themselves. Your husband is tracking a wounded gazelle and could be gone for days.

Meanwhile, the infant slung to your hip has started screaming and the distinctive sound triggers a release of oxytocin that causes your breasts to swell and leak. You have to feed her but you can’t do that and make sure your other children get enough to eat. There is a very real chance that some of them will be too weak to survive the next time fever breaks out unless you can get help.

You simply can’t be everywhere at once. It is a desperate feeling but these are the daily realities among the East African Hadza. If it wasn’t for your mother, already kneeled on the ground and using a stick to claw through several layers of tough sediment, it might have been your reality as well. While your baby makes soft cooing sounds as she suckles you can only feel grateful that you were the youngest child in your family, or else your mother might well have had an infant of her own to care for.

This scenario provides the backdrop behind a perplexing question about human evolution: the advent of female reproductive senescence. Between the ages of 45-50 all women undergo physiological changes commonly known as menopause that result in the cessation of ovarian function. Since most women live longer than 50, even in preindustrial and hunter-gatherer societies, this raises a profound evolutionary question: Why would a species “choose” to forego one-third (and sometimes as much as one-half) of their reproductive potential? As I’ve discussed previously, the leading explanation has become known as the “grandmother hypothesis.”

The grandmother hypothesis posits that women who stopped ovulating in their golden years were freed from the costs of reproduction and were better able to invest in their existing children and grandchildren, thus helping to ensure that more individuals with their menopause inducing genes thrived and had children themselves.

To understand why humans are unique in this regards we must first examine what happens in nonhuman animals. All species make tradeoffs between reproductive and somatic investment. An individual animal is considered to have high reproductive fitness if they leave more offspring than others in their population. But if an individual focuses exclusively on reproduction (perhaps because of a mutation that causes a novel behavioral trait) and therefore doesn’t invest in their physical health and growth, chances are they won’t live long enough to achieve high fitness. Their genes will not be well represented in the next generation and the behavioral trait overemphasizing reproduction will be discarded into the waste-bin of evolutionary history.

While there are a few excellent examples of species adapted for this kind of reproduction-heavy focus (such as the male wasp spiders who offer themselves up as a meal to their hungry mate), the preferred strategy in most species is to invest in both reproductive and somatic interests. To put this in economic terms, it is of little use to keep up on your car payment if that means you will fall behind on your mortgage and end up on the streets.

Figure 1. Chimpanzee (left) and human (right) life history and reproductive senescence. Yellow bars: juvenile years, green bars: childbearing years, purple bars: post-fertile years. Figure reproduced from Hawkes (2010) using data from Hadza hunter-gatherers.

Chimpanzees are a useful comparison since, along with bonobos, they’re our closest evolutionary relatives and we shared a common ancestor with them between 4 and 6 million years ago. As Kristen Hawkes reported in the May 11, 2010 edition of Proceedings of the National Academy of Sciences, chimpanzees undergo reproductive senescence between the years of 45 and 50 just like humans do. However, that is also the extent of their lifespan.

As Figure 1 above highlights, humans have a longer lifespan than chimpanzees but made a different life history tradeoff to spend several nonreproductive decades during their golden years. One possibility to explain this could be that our hominin ancestors simply adapted to have a longer life after our two lineages diverged. However, this doesn’t address why human fecundity wasn’t also extended as well. Natural selection is a reproductive fitness engine; if humans are the only species that have such a lengthy period of nonreproductive life it suggests there must be another factor involved that compensates for this gap.

This is where the grandmother hypothesis comes in. Multiple studies have suggested that it is the maternal grandmother’s assistance that is the most important. This is because, infidelity being what it is, grandmothers are more confident in their genetic relatedness to a daughter’s child than to a son’s. However, as it turns out, not all grandchildren are created equal and this can have a profound influence on how both maternal and paternal grandmothers offer their assistance.

As reported in the February 10, 2010 edition of Proceedings of the Royal Society, Cambridge biological anthropologist Molly Fox and colleagues show that, because of the way the X-chromosome is inherited by male and female offspring, grandmothers are more closely related to some grandchildren than others.

Figure 2. X-Chromosome relatedness between grandmothers and grandchildren. Maternal grandmothers (MGM) share 25% X-relatedness with both boys and girls while paternal grandmothers (PGM) share 0% X-relatedness with boys and 50% with girls. Figure reproduced from Fox et al. (2010)

The X-chromosome contains an estimated 1,529 genes and translates to roughly 8% of the total number of genes that humans have. During reproduction, paternal grandmothers will pass one of their X-chromosomes to her son (the Y-chromosome, of course, being supplied from the paternal grandfather). If her son later has a daughter he will pass on this same X-chromosome because it is the only one he has. This means that 50% of a paternal grandmother’s X-chromosomal genes will be represented in her granddaughter (see Figure 2).

However, if she instead has a grandson, none of her X-chromosomal genes will be passed on because her son will only pass on the Y-chromosome. Paternal grandmothers will therefore share more genes overall with granddaughters than with grandsons (the authors calculate an overall genetic relatedness of 31% with granddaughters but only 23% with grandsons).

Maternal grandmothers have a somewhat different genetic relationship with their grandchildren. They will also pass along one X-chromosome to their daughter but both granddaughters and grandsons will have a 50:50 chance that this same chromosome will be passed to them in turn. This means that maternal grandmothers share about 25% of their overall genes with grandsons and granddaughters equally. While this genetic variability may not seem very significant in the abstract, it could have very real implications for child survival.

If the grandmother hypothesis is correct we should expect to find that those children who receive grandmother assistance will have survival rates consistent with this genetic variability. The authors therefore make the bold prediction that boys will survive better when receiving investment from maternal grandmothers while girls will survive better with investment from paternal grandmothers.

To test this prediction the authors used data on child survival rates in the presence of grandmothers for seven populations of rural farmers separated in both geography and time: Japan (1671-1871), Germany (1720-1874), England (1770-1790), Ethiopia (1998-2003), Gambia (1950-1975), Malawi (1994-1997), and Canada (1680-1750). All of these populations lived without the benefits of modern scientific medical care and in an environment where a grandmother’s assistance could play an important role in child survival.

The results of this study matched the predictions beautifully. In all seven populations grandsons survived better in the presence of maternal rather than paternal grandmothers (p = 0.0081) while granddaughters survived better in six of the seven populations when they received assistance from paternal instead of maternal grandmothers (p = 0.0046). Culture certainly plays a role in how grandmothers interact with their grandchildren but, because these results were found in such diverse populations, it makes a strong argument that fitness benefits were the ultimate cause of these differences in grandmother investment. It also provides further support for the hypothesis that menopause is an evolutionary adaptation that allowed women to pass on more of their genes by helping their children have greater fitness instead of reproducing themselves.

It is important to point out, however, that this does not mean that all maternal grandmothers will prefer grandsons to granddaughters (or the opposite on the paternal side). There is never a one-to-one correspondence between statistical probabilities and everyday experience. However, on average, the general trend for Homo sapiens is to follow the same evolutionary forces that exist for any other species. Those traits that allowed more of an individual’s genes to be passed on to the next generation were selected for and those that did not were ultimately discarded. The evidence has been steadily advancing that menopause is not simply the result of women living longer than their chimpanzee counterparts but that it was an evolutionarily successful strategy that allowed more members of our species to survive and reproduce.

When living on the African savanna a grandmother’s assistance can literally be a matter of life or death. For several million years our ancestors lived an experience very much like the Hadza today and the struggles they faced have left their mark inscribed on our bodies. Those who are about to experience the hot flashes and emotional ups and downs that come with the physiological changes of menopause may take solace in the fact that their present discomfort is the very thing that helped our distant relatives survive.

If it wasn’t for the cessation of reproductive function our ancestors would have likely seen many more of their children and grandchildren face a bitter end. Thanks to the assistance of grandmothers our species has thrived to the point where many of us now no longer need their help. We owe them a debt of gratitude and, at the very least, periodic phone calls to thank them for everything they have done for us (even if they’re not really sure why).

References:

Hawkes, K. (2010). How grandmother effects plus individual variation in frailty shape fertility and mortality: Guidance from human-chimpanzee comparisons, Proceedings of the National Academy of Sciences, 107 (Supp. 2), 8977-8984. DOI: 10.1073/pnas.0914627107

Fox, M., Sear, R., Beise, J., Ragsdale, G., Voland, E., & Knapp, L. (2010). Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality, Proceedings of the Royal Society B: Biological Sciences, 277 (1681), 567-573. DOI: 10.1098/rspb.2009.1660

     "Darwin" by Nathaniel Gold

According to the British Medical Journal the alleged crime resembled a crucifixion. The victims had been strapped to boards, backs down, and with their legs cinched outwards. In the stifling August heat their heavy breathing was made only more intense by a suffocating fear. The accused was described as wearing a white apron “that was afterwards covered with blood” as he approached one of the individuals he had selected for his experiment. Their mouth was tied shut, but when the blade entered the thin, pink flesh of his inner thigh the cries of agony were simply too much to bear.

Experienced medical men in attendance, including some of the nineteenth century’s top surgeons, were outraged and demanded that the animal’s torture cease. Thomas Joliffe Tufnell, President of the Royal College of Surgeons in Ireland, denounced the demonstration as a “cruel proceeding” and stormed to the operating table to cut the dog loose.

Other physiologists objected to the interruption with one insisting, “That dog is insensible; he is not suffering anything.”

But Tufnell held firm, “The dog is struggling hard to get free. I am a sportsman as well as a surgeon, and I will never see a dog bullied.” However, a vote was taken among the assembled members of the British Medical Association and the demonstration was allowed to continue.

A tube was then forced into the conscious animal’s femoral artery, the white hair of his belly stained red as the arterial pressure caused blood to spurt from the incision. Into the tube the accused injected pure alcohol. The result, continued the Journal, “was an immediate struggle, which almost immediately subsided. The animal became dead drunk.”

“Now, you see he’s insensible,” a physician snidely remarked to Tufnell.

“Yes,” Tufnell replied, “and he’ll never be sensible again, for he will die.”

Spattered with gore from the comatose animal, the accused, Dr. Eugene Magnan of Paris, insisted he would be quite well by that evening. The dog soon died. Magnan then turned to the second animal, opening the same artery as before but injecting absinthe into the wound. According to witnesses:

The animal struggled much, cried as far as it was able, showed other symptoms of great suffering, and ultimately–not long after the injection–had a fit of epilepsy.

This had been the point of Magnan’s August 13, 1874 demonstration: the physiological effects of alcohol and absinthe on the animal nervous system. It had been made possible by four physicians based in Norwich, England, all of whom now stood trial for actions taken that did “unlawfully illtreat, abuse, and torture certain animals.” Dr. Eugene Magnan, also listed as a defendant, was not present in the courtroom since he had fled the country back to France. Because it could not be proven that the four English physicians had been actively involved in the demonstration the charges were ultimately dismissed, though the court ruled that the case against them was proper and required them to pay all legal costs. However, in the court of public opinion they were guilty as charged.

Animal experimentation, or vivisection as it was known in the nineteenth century, had already been practiced for centuries (William Harvey’s famous dissections of deer in the 1620s had revealed the heart’s role in the circulatory system) but with the rise of scientific medicine more animal subjects were being “put to the blade” in the name of science. The physician George Hoggan described his own experience taking part in some of these dissections with dogs:

Hundreds of times I have seen when an animal writhed in pain, and thereby deranged the tissues, during a deliberate dissection; instead of being soothed, it would receive a slap and an angry order to be quiet and behave itself. . . Even when roughly grasped and thrown on the torture-trough, a low, complaining whine at such treatment would be all the protest made, and they would continue to lick the hand which bound them till their mouths were fixed in the gag.

Darwin was well aware that these kinds of experiments took place, even using a similar example in his 1871 book The Descent of Man:

[E]veryone has heard of the dog suffering under vivisection who licked the hand of the operator; this man, unless he had a heart of stone, must have felt remorse to the last hour of his life.

As one of the most celebrated biologists in England, Darwin was both a supporter of experimental physiology and was passionate about protecting animals from cruelty. As a local magistrate he regularly came across cases of cruelty to farm animals and, according to his biographer Janet Browne, “was inexorable in imposing fines and punishment.” In 1853 he waged a “private vendetta” against a Mr. Ainslie for cruelty to his carthorses, threatening to “have him up before a magistrate & his ploughman also.” According to his son, Francis Darwin, the man who many saw as advocating “might is right” was as disgusted by animal cruelty as he was by the human cruelty he experienced in slave holding societies:

The remembrance of screams, or other sounds heard in Brazil, when he was powerless to interfere with what he believed to be the torture of a slave, haunted him for years, especially at night. In smaller matters, where he could interfere, he did so vigorously. He returned one day from his walk pale and faint from having seen a horse ill-used, and from the agitation of violently remonstrating with the man. On another occasion he saw a horse-breaker teaching his son to ride, the little boy was frightened and the man was rough; my father stopped, and jumping out of the carriage reproved the man in no measured terms.

This sympathy extended to animals used in experimentation, as Darwin wrote to the Oxford zoologist Ray Lankester in 1871:

You ask about my opinion on vivisection. I quite agree that it is justifiable for real investigations on physiology; but not for mere damnable and detestable curiosity. It is a subject which makes me sick with horror, so I will not say another word about it, else I shall not sleep to-night.

However, Darwin did not take his own advice and, after the media uproar following Magnan’s demonstration and the ensuing court case, the notoriously reclusive naturalist spearheaded a campaign to regulate how vivisection was conducted in England.

The year 1875 was a milestone for British animal rights activism. Building off the popular outrage over Magnan, the author, feminist, and animal rights campaigner Frances Power Cobbe formed the Society for the Protection of Animals Liable to Vivisection (and, later, the British Union for the Abolition of Vivisection, which continues to this day). With the assistance of sympathetic members of Parliament, Cobbe drafted a bill that would require regular inspections of physiological labs engaged in vivisection. Darwin heard of this activity through his daughter, Henrietta Litchfield, who was passionate about animal rights and had sent her father Cobbe’s petition to sign. Her letter had Darwin contemplating the issue “for some hours” and he delivered a considered and thoughtful response:

I conclude, if (as is likely) some experiments have been tried too often, or anesthetics have not been used when they could have been, the cure must be in the improvement of humanitarian feelings. Under this point of view I have rejoiced at the present agitation.

However, despite his conflicts over vivisection, Darwin’s opinion of the bill was that it would do little to protect animals and, at the same time, would result in a chilling effect on science:

[I]f such laws are passed, the result will assuredly be that physiology, which has been until within the last few years at a standstill in England, will languish or quite cease. . . I cannot at present see my way to sign any petition, without hearing what physiologists thought would be its effect, and then judging for myself.

Four months later Darwin, who rarely took any active role in politics, was in the midst of a political campaign to introduce his own bill to Parliament. As he wrote to his close friend Joseph Hooker, then-President of the Royal Society, “I worked all the time in London on the vivisection question . . . The object is to protect animals, and at the same time not to injure Physiology,” and he had already enlisted the support of “some half-dozen eminent scientific men.”

While protecting the scientific enterprise was an important aspect of what became known as the Playfair bill (after Dr. Lyon Playfair, the liberal member of Parliament who introduced the legislation), Darwin’s personal background advocating against animal cruelty and the fact that his son-in-law, Robert Litchfield, was the one who helped Darwin write the bill, it suggests that animal rights was just as much a part of Darwin’s concern. In fact, the Playfair bill went beyond Cobbe’s in the protection of animals by including the British Association for the Advancement of Science (BAAS) guidelines that required anesthetic in all experiments, including for teaching purposes. As historian David Allen Feller wrote in 2009 in his account of the 1875 antivivisection controversy:

Under the BAAS guidelines, not only was anesthesia required in experiments whenever possible, but an entire class of experiments, those conducted for mere demonstration purposes without any new scientific discovery in mind, were outlawed. This was not so under the [Cobbe] bill, which did not distinguish between classroom and purely scientific experiments. Inclusion of this provision of the BAAS guidelines was clearly intended by Darwin from the outset of his work on the bill. Darwin wrote to Burdon Sanderson and Huxley that he thought the BAAS guidelines would be the best compromise, and Darwin specifically noted the inclusion of a ban on the use of live animals for the purpose of demonstrative teaching.

Darwin is widely known for never taking part in any public discussions or debates on his theory of natural selection (leaving that to trusted friends such as Thomas Henry Huxley). His poor health and hatred of travel kept him at his estate in the countryside throughout most of his life. And yet, on the question of vivisection, Darwin not only traveled to London to help draft the Playfair bill, he returned when asked to testify by the Royal Commission when investigating the use of vivisection. During the questioning Darwin again insisted that experimentation on animals was important for the development of medical science. However, on the question of experiments carried out without anesthetic or ones inflicting pain unnecessarily, Darwin stated unequivocally that, “It deserves detestation and abhorrence.”

Those words became the basis upon which the Royal Commission recommended that vivisection be regulated. After quoting Darwin’s view in their report to the Queen, they went on to state:

This principle is accepted generally by the very highly educated men whose lives are devoted either to scientific investigation and education, or to the mitigation or the removal of the sufferings of their fellow creatures.

The following year The Cruelty to Animals Act of 1876 was passed by Parliament and signed into law.

Charles Darwin’s advocacy for animal rights has more than mere historical interest. Today it is commonplace for scientists, particularly those who work with animal models in their research, to oppose animal rights legislation as being fundamentally anti-science. However, as Darwin himself has demonstrated, it is possible (even necessary) for the pro-science position to be concerned with animal welfare. Being pro-science does not mean being pro-cruelty.

There are currently some very good laws in place throughout England, Europe, and the United States that protect animals from unnecessary suffering in the pursuit of medical knowledge. However, the differences between countries continue to raise concerns about how much suffering should be permitted in animal research. Last year saw the use of chimpanzees in medical experimentation banned throughout the European Union. At the same time, there are nearly 1,000 chimps used by federal researchers in the United States for vaccine, hepatitis C, and HIV research. Year after year legislation to ban the practice fails to gain support in Congress.

Ironically enough, many of the worst abusers of animals in the nineteenth century came from continental Europe, a region that is now the leader in animal rights legislation. If there is any justice in Eugene Magnan escaping prosecution for his actions 135 years ago, it may be that public outrage over his “demonstration” sparked a movement that, today, would provide him with no safe haven. There is little doubt that animal experimentation has resulted in some necessary medical breakthroughs. But, as in the nineteenth century controversy, Darwin’s own struggle with this research is something we would do well to remember.

References:

“Prosecution At Norwich. Experiments On Animals,” The British Medical Journal Vol. 2, No. 728 (Dec. 12, 1874), pp. 751-754.

Browne, J. (2002). Charles Darwin: The Power of Place. New Jersey: Princeton University Press.

Darwin, C. (1871). The Descent of Man, and Selection in Relation to Sex. New York: D. Appleton & Co.

Feller, D. (2009). Dog fight: Darwin as animal advocate in the antivivisection controversy of 1875 Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, 40 (4), 265-271 DOI: 10.1016/j.shpsc.2009.09.004

     "Funeral" by Nathaniel Gold

I had always been afraid of my grandfather and now I was staring at his pale, lifeless hand inches from my face. But the very same arthritic fingers I had seen him use countless times to push tobacco inside his pipe or the hard candies he loved into his toothless mouth now just looked wrong to me. They were alien and artificial. It was as if a sculptor had taken the man I knew and placed a life-sized replica in his coffin to fool us. I had to touch him. Later I would learn that this impulse wasn’t unique to that curious ten-year-old attending his first funeral.

In fact, no lesser a figure than the famous 17th-century English parliamentarian and diarist Samuel Pepys would be similarly tempted. After attending a public dissection at London’s Barber-Surgeons Hall one evening in 1663 he enticed his host to let him see the body alone, a sailor who had been hanged for robbery. Afterwards, in the flickering candlelight, Pepys wrote in his diary what I might have expressed myself if I’d had the vocabulary:

“I did touch the body with my bare hand; it felt cold, but methought it was a very unpleasant sight.”

There is something intensely animal about our relationship with the dead. As an atheist I don’t feel particular reverence or awe at the site of a cadaver. It mostly just creeps me out. But even religious believers, those who should be comfortable with the idea that a dead body retains no trace of the person they once knew, also seem to have trouble letting go of what St. Paul called “confidence in the flesh.” In funerary observances around the world cadavers are regularly touched, kissed, washed, anointed with oils, bedaubed with ceremonial makeup, carted to sacred ground, entombed with their clothes or belongings, and generally treated in death as if their body were going on a different journey than miasmic decay.

However, as is often the case where human universals are concerned, looking to similar behaviors in other animals can be especially instructive. For example, a study released in May, 2011 in the American Journal of Primatology has captured the most complete process to date of what could only be described as mourning behavior in nonhuman primates. Katherine Cronin and colleagues at the Max Planck Institute, Gonzaga University, and the Chimfunshi Wildlife Orphanage Trust in Zambia have documented a case where a chimpanzee mother faced what for most of us would be an unthinkable horror: the death of her child.

Video footage by Cronin et al. 2011.

The infant had been observed behaving sickly ever since birth when, on May 18, 2010, researchers saw the chimpanzee mother, Masya, carrying the dead body of her offspring. Masya continued to carry her lifeless child until the following day when observers were present to record what they saw next. The infant was placed in a clearing while Masya sat a short distance away staring at the motionless form. Researchers recorded over the next hour as the mother approached her offspring 23 times to place her hands on the child. 21 of these contacts were directed toward her offspring’s face or neck. At the end of this display Masya once again picked up her infant and carried her to the center of the social group about 20 meters away. When she laid her infant down the other group members, eight in total, proceeded to gently touch, stroke it’s belly, and groom it with straw. After about twenty minutes Masya retrieved the body and walked off. The next day Masya was observed on her own, she had let go of her dead child.

This is not the first time that primates have been observed to pay special attention to a deceased member of their group. In April last year similar behaviors were observed by a chimpanzee mother in Bossou, Guinea who ended up carrying her infant’s body for a total of 27 days. The mother, Jire, regularly groomed and slept next to her infant’s body and showed distress whenever they became separated. In 2000 a chimpanzee mother in the Mahale Mountains of Tanzania carried her infant’s body for nearly four months and individuals throughout the community were heard making distinctive vocalizations that the researchers had come to associate with fear and agitation. Other cases have been observed in the mountain gorillas of Rwanda, baboons of Ethiopia, macaques in Japan, and ring-tailed lemurs of Madagascar (see the timeline below).

There have also been notable examples of care being taken with the dead in African elephants and bottlenosed dolphins. In the case of the elephants, an ailing matriarch was observed to receive support from unrelated members of her group, behaviors that couldn’t be explained by either Hamilton’s theory of kin selection nor Trivers theory of reciprocal altruism. This concern with her body continued after death. Further study looked at how the group interacted with the bones of their former group mates and confirmed that the famous behaviors observed at elephant graveyards are intentional, individuals focused more intently on these remains than to other features of their environment. According to lead author Iain Douglass-Hamilton, these results challenge existing theories on where altruistic behavior ultimately comes from.

“The conclusion must be that elephants are interested in the sick, dying or dead elephants irrespective of genetic relationship,” he said. “There seems to be a generalized response to elephants in distress, rather than help or interest only being restricted to close kin.”

In a similar way to what primatologist Frans de Waal has documented in chimpanzees, the individuals appear to experience empathy with those who are sick or dead. But does this mean that nonhuman animals have a concept of death? According to Katherine Cronin in the case of the chimpanzee Masya, the behaviors are certainly suggestive of this.

“These behaviors would supply tactile and visual information about the current state of the body,” she said. The mother was intently observing her infant, her eyes rarely straying from the body as it lay in the sun. Likewise, as she was touching her baby’s face or neck, could note the absence of breath or lack of blood circulation warming her tiny frame. “Conceivably, this information could be remembered the next time she encountered the same set of cues,” Cronin said. In this way, the implications of death could be learned by chimpanzees.

Our desire to touch the dead, to adorn them in their Sunday best and wish them a final farewell, is the human process of gathering similar information. It is a way to reconcile our deep familiarity with the body of our loved ones with the realization that what they may once have been is no more. I’m not even certain that we have a concept of death beyond what we can tell from directly comparing what is different between the living and the dead. I certainly didn’t as a ten-year-old child shuffling past my grandfather’s coffin. In my desire to touch his cold hand I may have been fulfilling a need that many animals experience when confronted with their own realization of death.

Whether it’s a chimpanzee mother carrying her dead infant on her back, or what The New York Times reported of the woman from Plainfield, New Jersey who “talked to her dead infant as though it was alive” as she rode the crowded rail car home, the effect may be to ease our minds towards acceptance. For regardless of where we started in life, we all end up in the same place. Death is the great unifier and as we reach out to touch the dead, we are ultimately connecting with everyone else who is struggling to let go.

Reference:

Cronin, K., van Leeuwen, E., Mulenga, I., & Bodamer, M. (2011). Behavioral response of a chimpanzee mother toward her dead infant American Journal of Primatology, 73 (5), 415-421 DOI: 10.1002/ajp.20927

         "Greed is Good" by Nathaniel Gold

“Food is always more or less in demand,” wrote Adam Smith in The Wealth of Nations. While the founder of modern capitalism pointed out that the wealthy consume no more food than their poor neighbors, because the “desire of food is limited in every man by the narrow capacity of the human stomach,” the desire for material luxury “seems to have no limit or certain boundary.” Hunger, therefore, is the foundation of wealth.

“The poor, in order to obtain food,” Smith wrote, “exert themselves to gratify those fancies of the rich.”

The modern investor, epitomized by the insatiable appetite of Gordon Gekko from the movie Wall Street, has taken Smith’s advice to heart. But new financial instruments have now been introduced that have taken food inequality to levels unheard of in the eighteenth century. As it turns out, there is a downside to playing with your food.

Research now shows the uprisings in North Africa and the Middle East this year were triggered by spikes in global food prices fueled by speculators betting on the price of agricultural commodities [see my earlier piece Freedom to Riot: On the Evolution of Collective Violence]. This is the conclusion of a new study released today by Marco Lagi, Yavni Bar-Yam, Karla Bertrand, and Yaneer Bar-Yam of the New England Complex Systems Institute in Cambridge, Mass (pdf here). This financial speculation was made possible thanks to market deregulation under the Commodity Futures Modernization Act of 2000, the same legislation that introduced obscure financial derivatives like “credit default swaps” into the American lexicon and ultimately caused the collapse of mortgage and stock markets in 2007 and 2008.

“This analysis,” conclude the authors, “connects the bursting of the US real estate market bubble and the financial crisis of 2007-2008 to the global food price increases.”

Following this collapse many investors shifted their assets into “index funds” that allowed them to bet on the likelihood that commodity futures would increase. These index funds would be purchased by commodity traders and then repackaged as derivatives to be resold for twice or three times the initial purchase price. According to data from the United Nations, this investment rose from $13 billion in 2003 to $317 billion in 2008 (pdf here). This flood of cash caused intermittent bubbles as prices increased under artificial demand only to crash because there was no consistency in actual supply and demand (see Figure 1 below). In other words, as the price of food shot upwards many people were unable to buy the food that was actually grown.

Figure 1 - Impact of food prices on grain inventories. Food prices (blue line) grew out of proportion to global food production (green shaded area). Reproduced from Lagi et al. (2011).

According to Bar-Yam and colleagues, by September 2010 there was 140 million metric tons of grain sitting unsold in storage facilities around the world, an amount that would normally feed 440 million people in a single year. In the face of widespread global hunger, playing with food prices as if it were a casino pushed them beyond the ability of people to pay in regions of the direst need. Jean Ziegler, the UN Special Rapporteur on the Right to Food, has called this “a silent mass murder,” entirely due to “man-made actions.”

“We have a herd of market traders, speculators and financial bandits who have turned wild and constructed a world of inequality and horror. We have to put a stop to this,” he said.

The model that Bar-Yam and colleagues developed had earlier predicted the uprisings popularly known as the Arab Spring. On December 13, 2010 the researchers submitted a report to Congress warning of the link between rising food prices and global unrest. Just days later uprisings began in Tunisia followed soon after by Libya and Egypt, eventually spreading to 30 countries and toppling multiple governments. However, Bar-Yam and colleagues also predict that if global food prices continue to rise at their current rate the threshold that resulted in uprisings in the Arab world will become global between July 2012 and August 2013. In this context, the riots in London could be an early warning of greater conflagrations to come.

While Adam Smith may be known as the philosopher who first promoted the idea that “greed is good,” his earlier work suggests we are not condemned to exploit others for the benefit of a few. In his book The Theory of Moral Sentiments, written in 1759, Smith proposed that sympathy for the plight of those who suffer is an inherent part of human nature.

“When we see one man oppressed or injured by another,” he wrote, “the sympathy which we feel with the distress of the sufferer seems to serve only to animate our fellow-feeling with his resentment against the offender.”

With the current occupation of Wall Street and the international condemnation of an economic model that would take advantage of those most in need, we are witnessing Smith’s prediction in action. It is only when the reality of people’s suffering is hidden that greed is allowed to dictate policy. While our current system has chosen the greed of the few over the needs of the many, the intellectual founder of modern capitalism suggests it doesn’t need to be this way. “When we think of the anguish of the sufferers, we take part with them more earnestly against their oppressors.”

Reference:

Marco Lagi, Yavni Bar-Yam, Karla Z. Bertrand & Yaneer Bar-Yam (2011). The Food Crises: A quantitative model of food prices including speculators and ethanol conversion. New England Complex Systems Institute.
URL: http://necsi.edu/research/social/foodprices.html

Cover Art: Isaak Levitan, "Hunters Trekking Through a Winter Landscape" (1876).

Evolutionary biologist Lee Alan Dugatkin has made his career studying cooperation, so it makes perfect sense that the subject of his latest book would be an anarchist. In The Prince of Evolution Dugatkin tells the story of the Russian prince, evolutionary theorist, and political radical Peter Alexeyevich Kropotkin whose Darwinian theory of mutual aid was the first to argue that cooperation was an integral part of natural selection. Today, the quest to understand how cooperative behavior evolved is one of the hotest areas in the life sciences, though few researchers realize that many of their questions were first posed by Kropotkin more than a century ago.

“Kropotkin was not only the first person who clearly demonstrated that cooperation was important among animals,” Dugatkin writes, “he was the first person to forcefully argue that understanding cooperation in animals would shed light on human cooperation.”

Dugatkin’s book [an excerpt of which has been posted at Scientific American.com] is a précis on Kropotkin’s life and work, an overview that highlights the common theme of mutual aid in both his scientific and political ideas. Some may be familiar with Kropotkin as the revolutionary theorist of anarchism, a political system in which people organize their own affairs at the local level without interference from an external government, but few are likely to realize that this “anarchist Prince” started out as a physical geographer and geologist whose work was celebrated around the world. The discoveries that Kropotkin made of glacial formations during the Quaternary Period in Russia were received with international acclaim and earned him invitations to join the Imperial Russian Geographical Society, the British Association for the Advancement of Science, as well as a Cambridge University endowed chair in geology (which he turned down because it came with the stipulation that he give up his political work).

The Prince of Evolution offers a tantalizing peek into the life and ideas of a man Dugatkin calls “one of the world’s first international celebrities,” someone who filled auditoriums throughout Europe, England, and the United States with talks ranging from biology to anarchy to Russian literature. Kropotkin was a thinker whose ideas were so large that a single discipline could not contain them, and they were thought to be so dangerous that he was arrested multiple times and spent lengthy prison terms in Russia and France for communicating them. Part of what made him such a threat to the monarchs of Europe, Dugatkin suggests, was that Kropotkin refused to accept any authority that wasn’t based on scientific principles. He urged people everywhere to reject illegitimate tyranny and to use the tools of critical thinking and science to build a more equitable society themselves. As Kropotkin wrote in his Appeal to the Young (1880):

We need above everything to spread the truths already mastered by science, to make them part of our daily life, to render them common property. We have to order things so that all, so that the mass of mankind, may be capable of understanding and applying them; we have to make science no longer a luxury but the foundation of every man’s life. This is what justice demands. I go further: I say that the interests of science itself lie in the same direction. Science only makes real progress when a new truth finds a soil already prepared to receive it.

Lee Alan Dugatkin has likewise taken up this clarion call for science advocacy. As a Professor and Distinguished University Scholar in the Department of Biology at University of Louisville in Kentucky, he has published eight books and more than one hundred scientific papers in such journals as Nature, Quarterly Review of Biology, Proceedings of the National Academy of Sciences, and Proceedings of the Royal Society of London. He has also written for Scientific American ["How Females Choose Their Mates," April, 1998; "Jefferson's Moose and the Case against American Degeneracy," Feb., 2011], as well as New Scientist, BioScience, The Huffington Post and The Wilson Quarterly.

I had the opportunity to sit down with Dr. Dugatkin last week to discuss his latest project on the science of Peter Kropotkin and what we might learn from a notorious anarchist whose ideas continue to inspire and provoke to this day.

   "Lee Alan Dugatkin" by Nathaniel Gold

Eric Michael Johnson: One of the things that strikes me about Kropotkin’s work is how he always saw the world through his scientific lens. He insisted that any important political philosophy needed to be based in scientific principles and he dismissed Karl Marx for that very reason. He even called Marxism a cult.

Lee Alan Dugatkin: Not only did Kropotkin think of Marxism as a cult but he also referred to Berlin as their Mecca. He has a number of wonderful quotes like that. Everything that he did from his work on biology and geology to his work on anarchy to his work on prisons or the French Revolution were all done through the prism of science. He made a point of arguing that one of the things that separated the anarchist philosophy from other political systems, including Marxism, is that anarchism was based on scientific principles, and specifically those principles derived from evolutionary thinking. Even though Marxism claimed to be a scientific discipline, it was not based on a biological understanding of the world at all.

One of the things that he despised about Marxism is that it was based on the idea of ultimate government control, whereas Kropotkin wanted no government shackles on anybody. He thought it was good that they wanted to distribute resources more fairly, but he didn’t think the government should have that role. He thought that the distribution should take place without government and that it should happen more naturally. Kropotkin wasn’t advocating a violent expropriation of resources, even though he was not particularly outspoken against violence, but he himself didn’t see violence as the way to get there.

Johnson: Kropotkin was also highly critical of the excesses of capitalism. However, as you point out in your book, he used the work of the economist Adam Smith to argue against the very competition that most people assume Smith was advocating. Why would an anarchist turn to the father of modern capitalism to make his case?

Dugatkin: Yes, it’s a great question. Kropotkin saw the old Adam Smith and the young Adam Smith as dramatically different figures. The Adam Smith who wrote The Wealth of Nations was not somebody that Peter Kropotkin was particularly fond of for both political and philosophical reasons. But Adam Smith also wrote a book called The Theory of Moral Sentiments where he argued that empathy was the key to understanding human behavior. It was for this reason that people are good to one another. They undertake what Kropotkin would call mutual aid because they could see the world through the eyes of somebody else.

Kropotkin was enamored with that Adam Smith. But, for Kropotkin, Adam Smith didn’t go far enough because he only focused on moral sentiments with regard to humans. Kropotkin began to think that this same empathy was what drove mutual aid in animals and he was convinced that it would end up playing a critical role in understanding animal cooperation as well as human cooperation. So he took up with Adam Smith, but only the Adam Smith who wrote The Theory of Moral Sentiments, not the Adam Smith who wrote The Wealth of Nations who he saw as a capitalist troublemaker.

Johnson: You’ve written a good deal about the role of imitation and behavioral traditions in a variety of species. How does this and the modern science of epigenetics relate to the way Kropotkin discussed the theory of biological inheritance proposed by Jean-Baptiste Larmarck? Do you think Kropotkin’s perspective would be entirely out of place today?

Dugatkin: Kropotkin, particularly towards the end of his career, became very interested in Lamarckian inheritance. This was the idea that acquired characteristics, traits that were gained during an individual’s lifetime, could be passed down across the generations. I think he did this primarily because he was looking for a mechanism that could produce mutual aid extremely quickly. Kropotkin saw mutual aid emerging whenever environments got harsh, but this was happening at a time scale that was too quick to be encompassed by the slow and methodical pace of natural selection favoring some traits over others. He used Lamarck’s inheritance of acquired characteristics as a mechanism that could still promote mutual aid with an evolutionary underpinning but at a much faster rate. Kropotkin saw almost all biological and political change as something that happened in spurts. When it occurred it would occur quickly and it would occur intensely. But then there would be periods where very little was going on.

Johnson: This sounds a lot like the theory of punctuated equilibrium that would later be proposed by Stephen Jay Gould and Niles Eldredge.

Dugatkin: Yes. This is sort of a political version of punctuated equilibrium. Kropotkin saw that there was an episodic nature to major political change that maps nicely onto the punctuated equilibrium view of biological change.

Johnson: And epigenetics? Kropotkin was a committed Darwinist and rejected the idea that physical traits evolved the way Lamarck proposed. But, as you point out, his theory of mutual aid was based in animal cognition and empathy. There has been a great deal of work recently, most notably by biologist Michael Meaney at McGill University in Montreal, that has identified non-genetic heritable changes in cooperative behavior that occur based on environmental influences. What do you think epigeneticists would have to say about Kropotkin’s ideas?

Dugatkin: I think the epigeneticists today would be pretty happy with Kropotkin. There are a small cadre of folks who think that the inheritance of acquired characteristics may play a role in evolutionary change among nonhumans. But when it comes to human cooperation I think everybody understands that both classic Darwinian natural selection but also what amounts to the inheritance of acquired characteristics drive the evolution of human behavior. It’s a dynamic between cultural and genetic evolution. While most animal behaviorists today might dismiss the Lamarckian side of Peter Kropotkin as something that we shouldn’t even be talking about anymore, human sociobiologists would be much kinder to him.

Johnson: In your book you write that “for more than 80 years—until about the 1960s—Kropotkin’s ideas on mutual aid played a prominent, critical role in the study of behavior and evolution.” By that I assume you’re referring to the work of George C. Williams, William Hamilton, and John Maynard Smith who heavily criticized the concept of group selection and inaugurated what is sometimes referred to as “neo-Darwinism,” best known through the selfish gene theory of Richard Dawkins.

Dugatkin: Absolutely. The birth of sociobiology and behavioral ecology in the 1960s is also the death of Peter Kropotkin’s work within the animal behavior sciences. Until that point there were at least some people who were paying attention to Kropotkin’s work, not enough, but some people were paying attention. This was happening particularly in what was called the Chicago School of animal behavior that included folks like W.C. Alee, Alfred Emerson, and their colleagues. They paid real attention to Kropotkin. When G.C. Williams and Hamilton, as well as Richard Dawkins and E.O. Wilson, came around it was the death knell for Kropotkin because the idea that traits can benefit others at a cost to oneself was severely criticized, in many ways rightly so. But I think that Kropotkin was thrown out with the bathwater. I don’t think anybody in that selfish gene group really read Kropotkin. I’m fairly certain they didn’t.

Johnson: Kropotkin clearly seemed to be advocating an early form of group selection. But wasn’t Darwin often advocating this as well? There’s a well-known quote from his book The Descent of Man that “Those communities which included the greatest number of the most sympathetic members would flourish best, and rear the greatest number of offspring.” He goes on to argue how those groups would end up doing better than other groups, a textbook definition of group selection.

Dugatkin: Yes, this is the most famous group selection quote associated with Darwin. I did my work with researchers who developed some of this group selection theory, and they’re certainly very familiar with that quote. Darwin, I think, did believe that group selection played a role in structuring human societies. However, the amount of space that’s spent on group and community level selection is very small and it’s almost all in The Descent of Man. This is an argument that group selectionists and selfish gene folks have all the time. Darwin has a very Jefferson-like quality in this regard. Abolitionists and slave holders could both claim that Thomas Jefferson said “X” about slavery and therefore he’s really the founder of their movement. But Darwin certainly talked about group selection and Kropotkin picked up on it. He then expanded on it in ways that were much deeper than Darwin, but he could and certainly did trace it to Darwin himself.

Johnson: Kropotkin argued that communities, left to themselves, would emphasize mutual aid internally and he saw the feudal lords and early capitalists as parasites that were exploiting the community for their own personal benefit. After the blatant exploitation and corruption in the heart of America’s financial sector, do you think there is some truth to this assertion?

Dugatkin: Kropotkin would not have been at all surprised by what has happened in the United States over the last few years. He generally had a negative view of capitalism but, even more important, was his work on mutual aid in human evolution from early on through the medieval period. His research showed that over and over again people figured out a way to create small, interacting cooperative groups like the guilds in the Middle Ages. But the problem he found was that, as soon as these cooperative groups emerged, it immediately created selection pressures that favored parasites. These parasites would come in and suck up what they needed from individuals who were being good to one another and, eventually, cause the society to crumble. So, certainly, Kropotkin would not have been at all surprised by what has happened today.

I think this gets to the episodic nature of social change in Kropotkin’s view. As soon as you establish a cooperative society, you immediately create these dramatic forces that favor cheating. The question of how to stop that was one that Kropotkin was obsessed with. He thought the prison system was a terrible solution to this sort of problem, that what it did was create more people that were even more parasitic when they came out because of the terrible conditions they had to deal with on the inside. But I don’t know that he was happy with any particular solution that he came up with. He knew this was one of the big problems that was going to consistently have to be dealt with. But in his heart of hearts I think he envisioned that a properly conceived anarchist society with rules for curtailing this kind of cheating would work. What exactly those rules would be, I think that’s difficult to know. He had some ideas but I don’t think he was completely satisfied with any of them.

Johnson: In the nineteenth century Kropotkin felt that coming to a scientific understanding of community politics (with the goal of promoting a more cooperative society) was vitally important for the future of the human species. But he also lived during a time when disciplinary boundaries weren’t so rigid and a naturalist could still have something valuable to contribute in the arena of political ideas. Do you think his project still holds any meaning in the twenty-first century?

Dugatkin: I absolutely do. I would argue that this is one of the many points that show Kropotkin’s prophetic powers. In essence what we are seeing today, what people like E.O. Wilson called Consilience, is the bringing together of the sciences, social sciences, and the humanities with an underlying naturalist explanation for everything that occurs on the planet, including political interactions. The lines between people who are studying evolution, economics, political science, psychology, anthropology, etc., are slowly beginning to fade because people realize that the underlying theoretical framework for all of these disciplines is evolution. Kropotkin knew that even then. He was really the first person to show how consilience could be achieved and he showed it, not just to other scientists, but to anyone and everyone who would listen. And there were plenty of people that did.

     "Anarchy" by Nathaniel Gold

Police cars were overturned and shops looted as the mob descended on the city’s central square. Rioters tore the police station’s outer door off its hinges and “used it as a battering ram” to break inside. Others smashed their way into the city building where they assaulted government workers, shattered windows, and destroyed furniture.

The portrait of a powerful leader was pulled from the wall and sent dangling from a balcony as angry voices below cursed him and the other “fascists” believed responsible for their condition. One man, a lathe operator who had gone on strike, ran onto the balcony holding up two plates loaded with cheese and sausage. “Look and see what they eat,” he shouted to the crowd below, “yet we cannot get such food!”

The Novocherkassk riot on June 2, 1962, was Soviet Russia’s largest public uprising to date. More than two thousand took to the streets in response to the Communist Party’s decision to increase food prices by 30 percent at the same time that wages were being reduced. Workers walked out on the job, students left their classrooms, and men and women of all ages joined the chorus of protest. The crowd marched peacefully through lines of soldiers backed by armored vehicles that had been hastily assembled and went to voice their grievances directly with a communist government that claimed to be on the side of the worker.

But when authorities inadvertently fired on unarmed civilians the “noisy, aggressive, and far less reasonable members determined its focus and direction,” wrote historian Vladimir Kozlov in his book Mass Uprisings in the USSR (M.E. Sharpe Inc, 2002). Drunken fights and petty theft occurred alongside the anger over poverty and police brutality. From a crowd made up of individuals, each possessing the ability to make a free choice, something more powerful had been unleashed in which normal rules of conduct seemed not to apply.

“For some reason some kind of force filled me,” testified one of the rioters during his trial. “Until this day, I do not understand how I got into this. What kind of devil was it that asked me to go and forced me to enter into the police department?”

Collective violence, extending from riots to warfare, presents a challenge to our ordinary understanding of free will. Actions that would rarely be taken by an individual on their own seem to be embraced when supported by a larger group. This can occur in societies ranging from the communist regime of Soviet Russia to the capitalist free market of modern day England. Given this commonality, perhaps the collective violence of a riot can be best understood as a biological event in which evolved cognitive responses encounter a unique environmental threat. And if that is the case, do individuals caught up in such incidents have any choice in the matter?

The Evolution of Mob Mentality

“Imagine you’re on a bus,” explains Vaughan Bell, clinical research psychologist at King’s College London. “It’s full of people and you have to jam into an uncomfortable seat at the back.” Very little connects you with any of the other passengers and it is unlikely you would even give them a second thought.

Suddenly, multiple windows are smashed open and you discover that the bus is under attack by a group of thugs who are trying to steal people’s bags through the broken windows. You very quickly feel a common bond with the other passengers and willingly cooperate with them to help fend off the thieves. Extreme circumstances have pushed you into identifying with the group against a common enemy.

“You didn’t lose your identity,” says Bell, “you gained a new one in reaction to a threat.” As Bell points out in the case of riots, that threat is often excessive force from the police that turns a disgruntled crowd into an angry mob.

This scenario is what psychologists refer to as the Elaborated Social Identity Model of crowd behaviour. Each individual remains a rational actor, but has been primed by natural selection to identify with the group during a period of crisis. This well developed ingroup/outgroup bias is what has allowed our species to be the most cooperative of the primates, but certain conditions have the potential to turn us against our own community. While the psychology of collective behavior may explain why individuals join together once a riot is under way, it doesn’t explain why the riot would begin in the first place. As it turns out, our primate cousins offer a unique insight into this question. Nonhuman primates offer a window into the range of behaviors available to our evolutionary ancestors and the legacy that they have passed down to us.

“Collective violence,” wrote Harvard primatologist Richard Wrangham in the Annals of the New York Academy of Sciences, shows “a common human pattern evident in societies lacking effective central authority, manifested in ethnic riots, blood feuds, lethal raiding, and warfare.” Such aggression, he says, is directly related to that of nonhuman primates and demonstrates a common evolutionary history. As Wrangham earlier wrote in his book Demonic Males: Apes and the Origins of Human Violence, our primate origins “preceded and paved the way for human war, making modern humans the dazed survivors of a continuous, 5-million-year habit of lethal aggression.”

Wrangham is but the latest in a long history of evolutionary scientists to argue that collective violence is an adaptive feature of the human species. However, one of the earliest case studies to reach this same conclusion is actually, in the light of hindsight, a prime example arguing against this contention. By doing so, it offers a unique perspective into the factors that motivate collective violence in human societies and may even offer some clues about how to prevent it.

Anatomy of a Massacre

On October 27, 1930 a brief report in Time magazine described an attack that took place among a captive colony of 140 “Abyssinian” baboons that had been newly installed at Monkey Hill in the London Zoo. This was merely the latest outbreak in what would eventually be described as a massacre of more than two-thirds of the population.

According to the article, the attacks occurred when a young social outcast had “stolen a female belonging to the king.” He fled with his captive behind a hastily built barricade where an indignant crowd gathered and trapped the two inside. After “two days of siege” he attempted to escape from his sanctuary only to be brutally attacked and killed by the waiting mob. Each attack led to a counterattack by a rival alliance. After several years the death toll amounted to ninety-four individuals in all–two-thirds of them male. Among the deceased were fourteen infants, most of them strangled either by male attackers or by their own mothers.

What transpired on that barren landscape was carefully documented at the time by Solly Zuckerman (later Lord Zuckerman), a recent émigré who had just completed his doctorate in anatomy at the University of Cape Town in South Africa. Faced with such senseless brutality inflicted by one group member against another, Zuckerman speculated on what could have stirred the hostilities and then kept them going for so long. He eventually concluded that the cause was “social discord.” The death of one individual upset the political hierarchy, and violence ensued until stability was regained.

The massacre of Monkey Hill has since become a classic zoological case study revealing the danger of embracing a faulty assumption about “natural” behavior [see my interview with primatologist Frans de Waal for more on this topic]. Zuckerman assumed he was observing evolution in action and that natural laws had shaped these beasts to engage in lethal aggression. Like most biologists of the time, he accepted the view that primate social behavior followed a one-size-fits-all model that was unaffected by environmental factors. While human beings learn to rise above their bestial nature, animals are, well, simply animals. Or so the argument went.

“Behaviour is uniform,” wrote Zuckerman in The Social Life of Monkeys and Apes, published in 1932. “The common belief that the new environment [of captivity] grossly distorts the expression of these relationships has no foundation in fact. The pattern of socio-sexual adjustments in captive colonies is identical with that observed among wild animals.”

He couldn’t have been more wrong. A few decades later ethologist Hans Kummer confirmed this by comparing the behavior of captive baboons in Zurich with wild populations in Ethiopia. What Kummer found was that captive baboons showed many more aggressive acts than their free-ranging counterparts (nine times more for females and seventeen and a half times more for males). The massacre of Monkey Hill therefore represents a kind of controlled experiment on the potential dangers of social engineering, one that demonstrates the lethal consequences of flawed assumptions.

It is true that Abyssinian baboons, now more commonly referred to as Hamadryas after their scientific designation Papio hamadryas, are notorious for their aggressive behavior. But the levels of aggression that Zuckerman described have never been observed in the wild, not then or since. Zuckerman assumed that captive conditions had no effect on baboon society and so didn’t think it was relevant that more than one hundred individuals were enclosed in a facility that measured only 100 feet long by 60 feet wide. It never occurred to him that the social discord he observed had been manufactured, and that he was the cause. The inhumane treatment that left nearly 100 baboons dead was the ultimate, and tragic, result.

From Colony to Metropolis

Since the events of Monkey Hill, hundreds of studies with captive primates have shown that impoverished environments result in heightened aggression and antisocial behavior. Such behavior has been shown to significantly increase under conditions of overcrowding, when there’s a lack of novelty in food, entertainment, or social opportunities, when the population increases and the number of strangers in a colony grows, or, most crucially, when food is limited and/or fluctuates dramatically (see Honess and Marin, 2006 for a review of the literature). Any of these factors can greatly increase the level of stress that individuals experience and promote social discord.

As neuroscientist Robert Sapolsky has documented in multiple studies, social stress and aggressive responses are highly correlated. When these stressors are too great it can cause what would be an otherwise adaptive response to become exaggerated [see my post Stressing Motherhood: How Biology and Social Inequality Foster Maternal Infanticide for a detailed discussion of this process]. Often all it takes is the right conditions to trigger a violent response. But if multiple factors are present and persist it can result in sustained aggression or even colony collapse. In this way, stress-induced aggressive behavior is both adaptive and the result of environmental conditions; a response that can be exaggerated or distorted when living in captivity.

It should come as no surprise that one of the most important environmental factors involved in stress-induced aggression is food. Another classic, if somewhat cruel, study by Charles Southwick in 1967 found that increasing the amount of food in a captive colony of rhesus macaques by 25 percent decreased the amount of aggression by 50 percent. However, when a normal amount of food was restricted (by placing it in a single basket where it could be monopolized by a few high-ranking individuals) the level of overall aggression tripled and the number of violent attacks per hour was five times greater.

“The animals are especially quarrelsome and competitive when the food supply is restricted,” Southwick concluded dryly. But he added that “the increased tension and aggressivity of captive animals exaggerates certain types of phenomena, and hence the results must be interpreted in proper perspective with reference to natural situations.”

What was clear was that when all colony members had enough to eat aggression was cut in half. But when inequalities were introduced, so that only a few individuals enjoyed an excess while the majority went without, it was met with a violent response. These findings were subsequently confirmed and now form the basis for food policy in captive primate facilities around the world. Captive conditions are now understood to significantly alter animal behavior unless precautions are taken to both understand species-typical behavior under natural conditions and provide an environment that allows its expression. Can the same be said about human societies?

Figure 1. Major outbreaks of rioting in England (red lines) correlate with average price of wheat between 1780 and 1822. Figure by author using data from Archer (2000). Click image to enlarge.

In our own species, historical and sociological studies of factors contributing to collective violence have found some striking parallels with studies of captive nonhuman primates. For example, John Archer in his book Social Unrest and Popular Protest in England showed that major outbreaks of rioting between 1780 and 1822 correlated with high wheat prices (see Figure 1 above). In nearly all cases the riots were preceded by a sharp rise in price and once the price fell the incidence of riots fell with it. This isn’t to suggest that wheat price alone was the cause, or that a rise in price always resulted in a riot. But it does suggest that the two were correlated and that a rise in food price promoted the same kind of social discord that lay behind incidents of collective violence.

Identical findings were reported in a study by Marco Lagi, Karla Z. Bertrand and Yaneer Bar-Yam of the New England Complex Systems Institute in Cambridge, Mass. In their report, published August 11, the authors detail the close correlation between global food prices and the incidence of riots in North Africa and the Middle East (see Figure 2 below). In 2008 more than 60 riots occurred worldwide in 30 different countries during a peak in food prices. After declining temporarily in 2009, even higher prices at the end of 2010 and the beginning of 2011 coincided with additional food riots as well as the larger protests and revolts that have become popularly known as the Arab Spring. In contrast, there were relatively few incidents of collective violence when food prices were low.

Figure 2. FAO Food Price Index from January 2004 to May 2011 and the beginning dates of "food riots" and protests (red lines). Reproduced from Lagi et al. (2011). Click image to enlarge.

“The timing of peaks in global food prices and social unrest implies that the 2011 unrest was precipitated by a food crisis that is threatening the security of vulnerable populations,” conclude the authors. “Deterioration in food security led to conditions in which random events trigger widespread violence.”

These findings may also help to explain the timing of riots in England the week before this paper was published. As Bar-Yam and colleagues point out, while the uprisings in their study were associated with dictatorial regimes, rising food prices are likely to affect impoverished communities in otherwise wealthy nations as well.

“The price of bread has more than doubled in the past five years in England,” Bar-Yam explained via e-mail. “As in other parts of the world, London has a population of poor individuals vulnerable to food prices who are likely to engage in protests and participate in social disorder under these conditions.”

Ironically, it may have been the very policies promoted by England and other Western governments that lay behind these conditions. One of the main causes of the spikes in global food price, according to Bar-Yam and colleagues, was investor speculation that resulted in an economic bubble like the one that hit the housing market in 2008. Beginning in 2001, financial institutions like Goldman Sachs and Morgan Stanley in the United States as well as Barclays Capital in the UK successfully lobbied their respective governments to deregulate the commodities market. This allowed them to invent new financial products, known as derivatives, that caused an explosion of speculation and volatility in agricultural prices. According to data from the United Nations, this investment rose from $13 billion in 2003 to $317 billion by 2008. The price of food rose along with the value of these investments, creating a financial bubble that put increasing strain on those communities already on the edge.

England’s Conservative government also implemented austerity measures at the same time as the peak in food prices that rolled back many social programs that poor communities relied on. On November 10, 2010, for example, student protesters rioted when cuts to education caused tuition fees to nearly triple. Likewise, additional cuts targeted youth and community centers, medical coverage, unemployment and disability payments, child benefits, as well as housing and fuel subsidies for pensioners. England already had one of the most unequal societies in Europe based on the divide between rich and poor. Such austerity measures may have pushed this division to its breaking point.

An interactive map created by the Centre for Advanced Spatial Analysis at University College London makes clear that the riot outbreaks were clustered in the most economically deprived regions of the city. It was these regions that would have been most aversely affected by the austerity measures and, with a peak in both food and energy prices occurring at the same time, the environmental conditions were ideal for a triggering event that would push an already stressed population over into social discord.

This conclusion is further supported by an analysis of similar austerity measures throughout Europe during the 20th century conducted by economists Jacopo Ponticelli and Hans-Joachim Voth of the Centre for Economic Policy Research in London. According to their report Austerity and Anarchy: Budget Cuts and Social Unrest in Europe published in August, there was a “clear link between the magnitude of expenditure cutbacks and increases in social unrest.”

As Ponticelli and Voth point out, when expenditure cuts reached 1 percent or more of the nation’s Gross Domestic Product, the total number of demonstrations, riots, assassinations, and general strikes in a single year would increase by one-third compared to periods of budget expansion. When budget cuts reached 5 percent of GDP the number of incidents doubled (see Figure 3 below). According to London’s Financial Times, England’s current budget cuts are 4.5 percent of GDP.

Total amount of social discord (CHAOS) in Europe between 1919 and 2009 correlates with the value of budget cuts relative to GDP. Reproduced from Ponticelli and Voth (2011). Click image to enlarge.

It was in the midst of these environmental conditions that police fatally shot Mark Duggan on August 4th and allegedly beat a 16-year-old girl during what was reportedly an otherwise peaceful protest in response to the shooting.

“This was the triggering event,” says Bar-Yam, “that led to spontaneous wider violence.” After five days of rage the damage was estimated to be £200 million ($326 million) and resulted in the arrest of more than 3,000 people. “It makes sense that in the beginning, the people involved were people in need. The violence then cascaded to others, who took advantage of the social disorder for other reasons. Social disorder is contagious.”

As in London, the Novocherkassk riot forty years ago died down as those involved eventually dispersed, sobered up, or found themselves in jail. As the riot population declined, the shared social identity declined with it. But the rioters left behind a physical scar on the urban landscape, evidence of the rage shared by thousands of people during a time of acute environmental stress. However, while the collective violence may have waned, the political meaning of the events remained hotly contested. Soviet Premier Nikita Khrushchev announced that the Soviet rioters in 1962 were nothing more than “antisocial elements who spoil our lives” and condemned them all as “grabbers, loafers, and criminals.” British Prime Minister David Cameron would offer nearly identical words. Others, such as The Daily Telegraph’s former editor-in-chief Sir Max Hastings, would portray the rioters as little different than Zuckerman’s baboons from Monkey Hill, “wild beasts” who “respond only to the instinctive animal impulses.”

But what is to blame for such cases of collective violence–nature, or the unnatural conditions of modern life? While there may well be evolved responses that promote collective violence, research in captive primates suggest that these behaviors are heavily influenced by environmental stress. During the past year environmental conditions were just right for the triggering of social discord in our own society and, in the contagion that followed, violence quickly spread among a population predisposed to a shared identity.

For London and the cities throughout North Africa and the Middle East, it appears there was a free choice to riot after all. But the choice didn’t come from the rioters alone, it rose from leaders and policymakers and the larger society as a whole. Riots reveal a colony in discord. Many of us have acknowledged the widening inequality and economic decline of our most impoverished citizens–but we chose to ignore it.

Aleksandr Solzhenitsyn, after experiencing firsthand the inequality and injustice that emerged from the Soviet command economy, wrote that the Novocherkassk riot was the first indication that the Iron Curtain was beginning to unravel.

“We can say without exaggeration,” he wrote in The Gulag Archipelago, “that this was a turning point in the modern history of Russia.” Free markets are theoretically designed to be flexible so that they rapidly respond to the needs of individuals and society. If this assumption is flawed we will need an alternative. Human nature is not destined for social discord so long as we have the freedom to choose conditions that can reduce the potential for collective violence. But the question remains if we will do so.

Selected References:

Marco Lagi, Karla Z. Bertrand, & Yaneer Bar-Yam (2011). The Food Crises and Political Instability in North Africa and the Middle East. New England Complex Systems Institute. arXiv: 1108.2455v1

Jacopo Ponticelli and Hans-Joachim Voth (2011). Austerity and Anarchy: Budget Cuts and Social Unrest in Europe, 1919-2009. Centre for Economic Policy Research Discussion Paper. VoxEU: http://www.voxeu.org/index.php?q=node/6848

John Archer (2000). Social Unrest and Popular Protest in England, Cambridge University Press, p. 30.

Paul E. Honess and Carolina M. Marin (2006). Enrichment and aggression in primates. Neuroscience & Biobehavioral Reviews 30(3): 413-436. DOI: 10.1016/j.neubiorev.2005.05.002

Richard Wrangham and Michael Wilson (2004). Collective Violence: Comparisons between Youths and Chimpanzees. Annals of the New York Academy of Sciences 1036: 233–256. DOI: 10.1196/annals.1330.015

  "Chimp with Monocle" by Nathaniel Gold

From the introductions alone, you would have thought you were in a 19th-century gentleman’s club enjoying cigars and brandy. “There’s nothing like a prime rib dinner to boost a guy’s chances of getting lucky,” boasted ScienceNOW as he cleaned his monacle. The Daily Mail agreed with a harrumph, “As every Romeo knows, laying on a delicious dinner for two is one of the best seduction ploys.” Chuckling along with a wink and a nudge, MSNBC added, “A savory meat dinner goes a long way, as in all the way.”

Ostensibly, these articles were talking about chimpanzees, but it was made perfectly clear what they were getting at. Rupert Murdoch, naturally, got straight to the point. “The oldest profession isn’t restricted to humans,” FOXNews asserted, while The New York Post headline simply shouted “Chimpanzee Meat Market.”

In other words, dating is just another form of prostitution and evolution proves that he that pays gets play. For some reason the barriers were down. Talking about chimpanzee sexuality allowed journalists to let loose and express views they would rarely utter otherwise. Evidently people got the message, if the comments on Slashdot are any indication. A rare case of maturity could be found at Nature‘s The Great Beyond which wrote that:

News that female chimps mate more frequently with male chimps that share their meat with them has prompted a slew of at best corny, at worst downright sexist, even lewd, headlines.

The main problem was that, while everyone else was busy giggling over these chauvinist fantasies, they missed the real meat of the story.

The study in the journal PLoS ONE, by Cristina Gomes and Christophe Boesch of the Max Planck Institute for Evolutionary Anthropology, finally answered a question that has intrigued primatologists for nearly two decades. Do female chimpanzees preferentially mate with males who share their hunting gains with them? This hypothesis was first suggested in 1994 by Craig Stanford and Jane Goodall when they found that the best predictor for whether males would engage in a hunt or not was the presence of females with sexual swellings (large, fluid-filled sacs indicating the estrous phase of their reproductive cycle). However, subsequent studies could not find any evidence that hunting resulted in direct fitness benefits.

According to a study by Mitani and Watts, females with sexual swellings only received meat on 23 occasions out of 68 attempts and, of those, just 14 resulted in matings. Only a third of all estrous females got meat when they tried for it. In contrast, males were almost four times as likely to share meat with another male involved in the hunt than with an estrous female. When meat was shared with an estrous female, only slightly more than half chose to mate with the male who offered it. The “meat-for-sex” hypothesis appeared to be flaccid. And yet, strangely, there were few sensationalist news reports touting evidence of bromance among our evolutionary cousins.

However, Gomes and Boesch suggested a different approach. What if females remembered the male who shared with them and chose to mate with them at a later time? Over a period of 22 months in the Taï Forest of Côte d’Ivoire the researchers recorded every case of meat sharing (both with estrous and anestrous females), noted who was sharing the meat with whom and identified all of the mating partners during the study period. They also measured grooming, sharing of additional food items and the number of times males assisted females in conflicts with other individuals. Their results indicated that:

[F]emales copulated more frequently with males who shared meat with them at least on one occasion, than with males who never shared meat with them.

The authors were able to eliminate all other variables as significant factors except for male rank, which was independent of meat sharing. The final conclusion was that females were expressing two mutually exclusive choices (see Table 1 below). The authors spelled it out plainly:

Male rank and sharing meat with females had independent effects on male mating success, indicating that females copulated more with males who shared meat with them and with males of high rank.

Table 1. Factors influencing sexual activity between males and females. P-values lower than 0.05 are statistically significant indicating that both "Sharing meat" and "Male rank" were important for male mating success. Reproduced from Gomes & Boesch (2009). Click image to enlarge.

The larger story lay not in the fact that females preferred to mate with males who provisioned them, but that they were opportunistically shifting their mating strategies for their own reproductive interests. In earlier studies by Boesch at the same site it was demonstrated that 84% of undesirable advances were rejected by females (Stumpf & Boesch 2006; pdf here), promiscuous mating was reserved for the early part of estrous and that 93% of all copulations were terminated by females (Boesch et al. 2006; pdf here). Females chose who they would mate with, when they would mate with them and how long it would last.

Crucially, as Boesch also determined, ovulation generally occurred between five to eight days after maximum tumescence (when their sexual swellings were largest). By focusing on promiscuous mating in the early part of estrous, females were effectively ensuring that fertilization was less likely. In the later part of estrous females preferred a selective strategy and were much more likely to engage in “consortships” (where a female and male dyad would disappear for several days). This would ensure that the desired male ended up being the father of her child. As a result of these flexible strategies Boesch found that alpha male mating success fluctuated wildly, ranging from 67% to 38% over a 14 year period (Boesch et al. 2006; pdf here). These same shifting and opportunistic strategies have also been observed in populations at Mahale and Gombe.

Unfortunately, this study by Gomes and Boesch didn’t measure when in the estrous cycle females chose to mate with males who shared their hunt. It may be that females were reserving the early period of estrous for them and the more fertile period for males of higher rank. However, it could also be that those who demonstrated themselves willing to share were viewed as a better long-term investment. The bottom line however is that females were the ones calling the shots, and males understood that there were only two ways to prove they were serious.

Rather than such hackneyed cliches as “Sex sells, even in the rainforest” (Cosmos) or “The way to a chimp’s heart is through her stomach” (Wired) the real story was that female chimpanzees demonstrate flexible and opportunistic strategies to maximize reproductive success. Furthermore, because the sharing of meat was primarily with anestrous females and because there was no relationship between the amount of meat provided and the number of copulations, suggesting that this had any connection to prostitution or buying someone an expensive meal in order to “get lucky” was to completely miss the point. In all likelihood, females were using these exchanges to determine who would be the best potential father for her offspring over the long term. High rank has its advantages, but so does the guy who’s willing to share.

Reference:

Gomes, C., & Boesch, C. (2009). Wild Chimpanzees Exchange Meat for Sex on a Long-Term Basis PLoS ONE, 4 (4) DOI: 10.1371/journal.pone.0005116

      "Chimp Pope" by Nathaniel Gold

There is very little known about the reign of Pope Benedict III except that clerics were generally satisfied with his testicles. Upon his coronation in 855 AD God’s chosen messenger on Earth sat in a special chair resembling an ancient commode while the Holy See checked to make sure that the papacy was indeed infallible.

Two reliable clerics touched his testicles; witnesses who presented legal evidence of his maleness. . . At this the priest and the people responded, “Deo gratias” [Thanks be to God].

After all, you couldn’t be too careful. The Bible was very clear that, “He whose testicles are crushed or whose male member is cut off shall not enter the assembly of the LORD.” Healthy genitalia was a sign of spiritual purity and the Church made a point to check beneath the mantum of every Pope until up through the fifteenth century.

Of course, Christianity wasn’t alone in this respect. The ancient Greeks saw the penis as a gauge to their proximity with the Gods, the Hindu god Shiva is worshipped primarily by paying homage to his penis, or linga, and the Sumerian god Enki was thought to have brought life to the Tigris Valley when he “lifted (his) penis [and] brought the bridal gift.” The Pope seems to have merely been the latest in a long line of devout men who were dropping their pants for the Lord.

Now, scientists have gotten in on the act and have sought to understand human origins by studying our own little Bishop. From the standpoint of evolutionary biology this male obsession with their own genitalia makes perfect sense. Every animal alive today is able to stand and be counted because of a long line of ancestors who successfully reproduced. The natural world is a living erotic museum filled with variations in male genitalia, illustrating how natural selection has paid nearly as much attention to the male member as Catholic priests have.

But there’s a sinister side to this obsession, by which of course I mean penis spines. Throughout the Order Primates, as well as in many other mammal species, males have developed small (and sometimes not so small) keratinized structures along the head and/or shaft of their penis that have been adapted to maximize reproductive success. According to the, rather appropriately named, primatologist Alan Dixson in his book Primate Sexuality, these spines can be simple, single-pointed structures like in macaques or complex ones with two or three points per spine like in the prosimians (lemurs and lorises). These different forms of penis spine therefore suggest different mating strategies that various species have adopted during their evolution.

Examples of penile morphologies in primates. Note the obvious spines on I and K and the dots on N. Top row: Eulemur fulvus, Saimiri boliviensis, Macaca arctoides (stump-tailed macaque). Bottom row: Macaca fuscicularis (long-tailed macaque), Papio cynocephalus (baboon), Pan troglodytes (chimpanzee). Reproduced with permission from Dixson (2009).

However, a new study in the journal Nature has generated a great deal of titillation this week as Cory McLean and colleagues have revealed a sequence of DNA that promotes these penis spines, a sequence that humans appear to have lost. The genetic mechanism involved has already been explained extremely well by Ed Yong and John Hawks. However, the interpretation of what the loss of this DNA reveals about human evolution is perhaps the most provocative claim and has resulted in a flurry of media attention.

“Simplified penile morphology tends to be associated with monogamous reproductive strategies in primates,” write the authors. According to their study, the loss of these spines would have resulted in a reduction in sexual sensation (because the spines are thought to be connected to nerve endings) and would therefore have allowed our ancestors to engage in more prolonged sexual activity that the authors associate with pairbonding and the evolution of social monogamy (citing Owen Lovejoy’s Ardipithecus ramidus paper from 2009 as a model).

As Nature News wrote in their summary of these results:

It has long been believed that humans evolved smooth penises as a result of adopting a more monogamous reproductive strategy than their early human ancestors. Those ancestors may have used penile spines to remove the sperm of competitors when they mated with females. However, exactly how this change came about is not known.

This is where it’s important to know precisely what it is that we’re talking about. Nature News referred to these structures in chimpanzees as “penis spikes” when the reality is more akin to goose bumps. Scicurious has posted a review of the only study that seems to have been done on these structures (published by W.C. Osman Hill in 1946) that found these “spines” to be only about 0.35mm wide, or the thickness of a human hair. Hardly a structure that would be useful for removing sperm.

Another problem is McLean et al.‘s argument that loss of penis spines would result in reduced sensitivity and longer bouts of sexual activity. As Dixson points out in Primate Sexuality (p. 118), orangutans have more elaborate penis spines than chimpanzees do and yet their average duration of sexual activity is significantly longer than either chimpanzees or humans. Chimps engage in sexual activity for an average of 8.2 seconds while the average for humans (based on Kinsey’s data) is less than 120 seconds. In contrast, orangutans range between a median of 840 seconds and a maximum of 2,760 seconds. Humans actually rank 14th in the duration of sexual activity (also falling behind macaques).

However, there’s a more serious problem with the argument presented in this study. The source the authors cite in support of their argument for smooth penis monogamy is Dixson’s Primate Sexuality, however he doesn’t discuss what penis spines indicate about primate mating systems in that book. That’s in his later book Sexual Selection and the Origins of Human Mating Systems, where his conclusions are somewhat different.

Four penile morphologies in single-partner or multi-partner primate mating systems (including humans). All categories show a significant difference except for penis spines. Reproduced with permission from Dixson (2009).

As Dixson’s graph indicates, there are significant differences between a single-partner mating system (monogamy or polygyny) and a multi-partner mating system on three of the four categories: penile length, baculum length, and distal complexity. The only penis morphology type that isn’t significant are penis spines. This doesn’t necessarily invalidate McLean et al.’s argument for increased pairbonding, but it doesn’t support it either. It shows that there is no correlation between penis spines and primate mating systems, the correlation that McLean et al. is arguing for. In contrast, Dixson concludes that Homo sapiens is a polygynous species. However, other factors suggest that a multi-male multi-female system is more accurate given the diversity of human sexuality.

There’s also one final thing. Humans may not have lost their penis spines. Dating back to 1700 anatomists have identified what have now become known as pearly papules (also called Hirsuties coronae glandis). As reported by Denniston, Hodges, and Milos in 2009:

We have shown that, in the chimpanzee, these papules are a normal feature (spine-like) and are associated with nervous structures. It seemed to us that, in man, they may be a return to an earlier morphology.

To see a picture of these human “penis spines” click here [NSFW].

Five studies have been done involving nearly 2,000 patients in three separate countries, with an estimate that about 30% of all men develop these papules. In contrast, only four chimpanzees were studied in Hill’s 1946 paper on penis spines so it’s unknown how prevalent these structures are even within genus Pan. As Hill notes in his study:

The spines of the Chimpanzee are simpler structures than those of any of the other Primates, and the question arises as to whether they are degenerate remnants of a once powerful armature or a new product of evolution.

While the genetics of these pearly papules have yet to be studied, it doesn’t seem that a strong case can be made yet for significant differences between our two species on this point. John Hawks goes on to note that the chimpanzee version can even be implanted into transgenic human foreskin fibroblasts:

That indicates that the overall genetic system to make penile spines is still there lurking in our genomes. If we could turn on the gene at the right time, replacing the function of the enhancer, we can still grow penile spines.

I’m confident that the bulk of this week’s Nature paper will offer a host of tantalizing insights into the ways that humans and chimpanzees have travelled down different evolutionary paths since our common ancestry. At the same time, our evolutionary history has primed some members of our species to seek firm answers by looking to their respective, er, members. As we sit and try not to think about Pope Benedict’s balls, we can muse on how potential revelations may indeed develop from these investigations. But it’s also possible that we’ll only be greeted with a cold hand and a cheap thrill before moving on to the next study.

McLean, C., Reno, P., Pollen, A., Bassan, A., Capellini, T., Guenther, C., Indjeian, V., Lim, X., Menke, D., Schaar, B., Wenger, A., Bejerano, G., & Kingsley, D. (2011). Human-specific loss of regulatory DNA and the evolution of human-specific traits Nature, 471 (7337), 216-219 DOI: 10.1038/nature09774

"Sharing is Caring" by Nathaniel Gold

Charles Darwin had more in common with chimpanzees than even he realized. Before he was universally known for his theory of natural selection, the young naturalist was faced with one of the great moral choices in the history of science. The decision he made has long been hailed as the type of behavior that fundamentally separates humans from other apes. But a new study reveals for the first time that thinking of others unites humans and chimpanzees in a cooperative bond that reaches across two epochs to the very evolutionary ancestor Darwin predicted.

On the morning of June 18, 1858, a parcel arrived that threatened to undo the originality of Darwin’s masterwork. Alfred Russel Wallace, a friend of Darwin’s who was then conducting field research in Borneo, sent his colleague a theory of evolution that closely matched what Darwin had secretly been working on for more than two decades.

“Even his terms now stand as heads of my chapters,” Darwin wrote, almost in a panic. “So all my originality, whatever it may amount to, will be smashed.”

What should he do? Borneo was thousands of miles away, what if the package had never arrived? After all, mail was lost at sea all the time. Darwin could publish his theory immediately and take his chances with any awkwardness he might face with his friend down the road. But that’s not what he chose to do.

“I would far rather burn my whole book than that he or any man should think that I had behaved in a paltry spirit,” he wrote to Charles Lyell, his friend and mentor. “He does not say he wishes me to publish; but I shall, of course, at once write and offer to send to any journal.” And so Wallace’s outline was included alongside an abstract of Darwin’s theory and presented jointly before the Linnaen Society the following month. Rather than receive a reward all to himself, Darwin made a prosocial choice so that his colleague could receive one as well. On the Origin of Species was published just over a year later.

This kind of prosocial behavior, a form of altruism that seeks to benefit others and promote cooperation, has now been found in the species that Charles Darwin did more than any other human to connect us with. A paper released today in Proceedings of the National Academy of Sciences by Victoria Horner, J. Devyn Carter, Malini Suchak, and Frans de Waal of the Yerkes National Primate Research Center at Emory University in Atlanta, Georgia, is the first to document spontaneous prosocial choice by chimpanzees, a species that, until now, was thought to be “indifferent to the welfare” of others.

Figure 1. Drawing of chimpanzees in the test setting. While her partner (left) watches through a mesh partition, the actor (right) reaches into a bucket with 30 tokens, 15 of each color, to select one and hand it to the experimenter. A reward is handed either to the actor or to both chimpanzees. Drawing by Devyn Carter from a video still.

The researchers made their breakthrough by presenting chimpanzees with a simplified version of the same moral test Darwin faced 150 years ago. Pairs of chimpanzees were brought into the testing room where they faced each other separated only by a wire mesh (see Figure 1). On one side was a bucket containing 30 tokens that the chimpanzee could give to an experimenter for a food reward. Half of the tokens were of one color that resulted in a selfish outcome in which only the chimpanzee who gave the token received a reward. The other tokens were of a different color that resulted in a prosocial outcome in which both chimpanzees received a food reward. The individual making the selection was rewarded no matter what. Their only choice was whether or not their “colleague” would benefit as well.

Figure 2. Prosocial choices by chimpanzees during experiment were significantly higher than no-partner controls (**P < 0.001, NS = not significant). Reproduced from Horner et al. (2011).

Because the individual making the choice always received a reward there was no incentive in the test design to encourage the prosocial option. The choice was each individual’s alone. Twenty-one pairs were tested in all, with each individual repeating the test on three different occasions and never sitting across from the same partner twice. If chimpanzees were indeed motivated only by selfish interests it would be expected that they would be more likely to choose a reward only for themselves (or it should be 50-50 if they were choosing randomly). But individuals were significantly more likely to choose the prosocial outcome compared to the no-partner control, indicating that Pan troglodytes clearly considered others when making their choice (see Figure 2).

“Offered a free choice between a prosocial and selfish option,” the scientists conclude, “chimpanzees overwhelmingly favored the former to the advantage of their partner.” Like Darwin, the chimpanzees in the study made a prosocial choice and decided to share the reward rather than enjoy it all for themselves.

This result should not be surprising to those who have followed De Waal’s research (see my in-depth interview about his work here) as well as similar studies concerning primate cooperative behavior. For example, bonobos (Pan paniscus) are as closely related to humans as chimpanzees are (sharing 99.3% and 99.2% of our DNA respectively) and have previously been shown to cooperatively share their food with others. Researchers Brian Hare and Suzy Kwetuenda working at the Lola ya Bonobo Sanctuary in the Democratic Republic of Congo reported last year that bonobos, when given the choice, “preferred to release a recipient from an adjacent room and feed together instead of eating all the food alone.”

Earlier studies have shown that chimpanzees engage in spontaneous altruism when witnessing an unfamiliar chimp trying to reach food on the other side of a door. As reported last year by Alicia Melis, Michael Tomasello, and colleagues, chimpanzees were much more likely than not to pull a chain that offered access to this food even though the altruist received nothing themselves. Chimpanzees have also been shown to provide assistance when presented with an unfamiliar human struggling to reach an object just out of reach. In 2007 Felix Warneken and colleagues found that chimps behaved identically to human toddlers under this scenario and were only too willing to help a stranger in need, even if that meant climbing over a series of obstacles in order to do so. Offering a reward for their assistance had no effect on the display of generosity in either study. Service, it seems, was its own reward.

The current study by Horner and De Waal now joins this chorus of research that reverses a decade of scholarship claiming that humans are profoundly different where it comes to regarding others. According to a highly reported 2005 study in Nature “chimpanzee behaviour is not motivated by other-regarding preferences” because individuals did not share food with others under a specific testing procedure. A 2006 study in Proceedings of the Royal Society insisted that another failed experiment meant that “chimpanzees made their choices based solely on personal gain.” Scientists are usually trained to avoid citing negative results as evidence that something does not exist, because a null hypothesis cannot be proven. Unfortunately, this is often forgotten.

Based on these kinds of negative findings researchers in the social sciences and humanities boldly concluded that humans were the only species capable of engaging in altruistic or prosocial behavior. Just this year, famed cultural anthropologist Marshall Sahlins wrote that, “non-human primates live by themselves and for themselves” while the economists Ernst Fehr and Urs Fischbacher wrote in a review article for Nature that prosocial behavior in nonhuman animals is “largely restricted to kin groups” making human societies “a huge anomaly in the animal world.” The economists Samuel Bowles and Herbert Gintis even went so far as to claim “human cooperation is the result of human capacities that are unique to our species.”

As Carl Sagan famously wrote, “Absence of evidence is not evidence of absence.” In a clear illustration of this dictum, Horner and De Waal determined that it was not that chimpanzees are motivated only by selfishness as these earlier reports contended. The tests that were designed to measure chimpanzee behavior were overly complicated and resulted in false conclusions.

“The chimps had to understand a complex food-delivery system,” De Waal wrote to me via e-mail, “and were often placed so far apart that they may not have realized how their actions benefited others. Our experiment is the first to avoid an apparatus altogether. Of course, our study also provides a warning against negative findings.”

In order to preempt the standard criticisms, their study also controlled for variables such as dominance rank, kinship, and the potential effects of punishment. Low-ranking individuals were not found to share more often with high-ranking individuals and there was no difference found between relatives and non-relatives. Likewise, when observing individuals together following the test, there was no correlation between their choice and the level of grooming or contact directed towards them afterwards, showing that chimpanzees were not punished for making the wrong choices.

“Intimidation behavior evidently did not help the partner’s cause, thus contradicting suggestions in the literature that chimpanzees share only under pressure,” the researchers conclude. “Nevertheless, we cannot rule out the possibility that chimpanzees in our study were influenced by reciprocal exchanges outside the experimental setting such as food sharing, increased grooming, or agonistic support.”

It is this latter possibility that shows exciting research opportunities for the future. Chimpanzee society, like the greater scientific community who studies them, is largely built around such reciprocal exchanges. Science is a social activity and sharing the rewards from one another’s research is what allows scientists to improve their work over time. Charles Darwin understood this and built a network of collaborators that allowed his theory to be as solid as possible. It simply wouldn’t have occurred to him to take full credit for the work that relied on the assistance of so many others.

“My Book, if it will ever have any value, will not be deteriorated,” Darwin wrote as he considered no longer being the only one to reap the rewards of his evolutionary research, “as all the labour consists in the application of the theory.” Darwin, like the chimpanzees he would bond us with, recognized the utility of sharing the rewards with others. Behaving in a “paltry spirit” was not the proper choice for a cooperative ape.

Reference:

Victoria Horner, J. Devyn Cartera, Malini Suchaka, and Frans B. M. de Waal (2011). Spontaneous prosocial choice by chimpanzees Proceedings of the National Academy of Sciences : 10.1073/pnas.1111088108

"Mendeleev" by Nathaniel Gold

The scientist who systematized all the known elements in the universe was about to throw everything away for love. In April, 1881 Dmitri Ivanovich Mendeleev was internationally renowned for his creation of the periodic table that revealed the simple, yet elegant structure underlying all matter, but he was prepared to kill himself unless the woman he loved agreed to marry him.

Anna Ivanovna Petrova, a twenty-year-old art student from the small Cossack village of Uryupinskaya in Southern Russia, had already turned him down twice in the last three years. Now the famous scientist had followed her to Rome where Anna’s father sent her to study (and to keep her beyond the reach of Mendeleev’s advances, who, after all, was forty-seven years old and married with two teenage children). But the man whose passion for science drove him to harness the mysteries of atomic valence was ultimately overpowered by elements of human chemistry that he could not control.

Of course, Dmitri Mendeleev wasn’t supposed to survive long enough to take his own life. Nearly thirty years earlier, on June 7, 1855, dense black clouds had filled the St. Petersburg sky like “a thick hanging of mourning drapery.” Across the Neva river the bells of St. Isaac’s Cathedral tolled beneath its golden dome, announcing the arrival of the Imperial yacht and its attending funeral procession. From his hospital room at St. Petersburg State University Mendeleev could have watched as the casket of Tsar Nicholas I was transported into the still unfinished Orthodox church, flanked by bishops in their purple velvet mitres. The sudden death of the Tsar, from an illness contracted during the Crimean War, would have offered ample opportunity for Mendeleev to contemplate his own impending mortality.

St. Isaac's Cathedral Today, St. Petersburg, Russia, Photo by Author

After experiencing frequent complications due to tuberculosis and “spitting blood,” doctors told the young chemistry student that he only had a short time to live. He was merely awaiting his journey to a drier climate later that summer and the remote chance he might survive. Remarkably, Mendeleev avoided the same fate that took the lives of both his mother and older sister to complete his thesis on chemical isomorphism that very year. He earned a gold medal for excellence with this freshman research and embarked on a scientific trajectory whose ascent few could ever imagine might fall.

After his full advancement to Professor of General Chemistry at St. Petersburg State University, and frustrated that no Russian textbooks existed on the topic, Mendeleev determined that he would write one himself. Spanning four volumes and taking three years to complete, his Principles of Chemistry adopted a personal, conversational style that spoke directly with the reader so that he could properly communicate both the evidence necessary for work in the laboratory and, more importantly, the philosophical underpinnings of the scientific process.

“Experimental and practical data occupy their place,” he wrote, “but the philosophical principles form the chief theme of the work.” For Mendeleev, science wasn’t simply a practical tool, it was a journey of passion and creativity that he emphasized in all of his scientific communication.

I have endeavored to incite in the reader a spirit of inquiry, which, dissatisfied with speculative reasonings alone, should subject every idea to experiment, encourage the habit of stubborn work, and excite a search for fresh chains of evidence to complete the bridge over the bottomless unknown.

Mendeleev Statue, St. Petersburg State University, Photo by Author

This was the same spirit of critical inquiry that he shared with his students in the classroom, speeches that would be followed by “thunders of applause” from his attentive audience.

“During the whole lecture,” wrote his student V.E. Grum-Grzhimailo, “[Mendeleev] taught us how to observe phenomena of everyday life and how to understand them… He imparted on his pupils his skill in observing and thinking, which no one book can give.”

But Mendeleev’s holistic approach to explaining material reality when reduced to its chemical constituents was not always popular with his university colleagues. Some felt “he had too many ideas [while] concerning narrow specific problems, he lacks patience.” The common approach at the time was to teach science through the memorization of established truths, like the rows of Latin verbs that Mendeleev was punished for reciting incorrectly as a boy.

“[T]he chemist of his day was more occupied in adding to the chemical facts than in speculating on the relation between them,” Lord Ernest Rutherford, the British Nobel Prize Winning chemist, would later remark. But it was Mendeleev’s unique combination of an empirical methodology with a speculative nature that drove him to envision novel interpretations of the chemical evidence.

Mendeleev's 1869 periodic table, Wikipedia

The central problem that chemists faced in 1869 was that there were 63 known elements (today there are 118, though just 94 are naturally occurring) but there was no explanation for the clear patterns that could be observed between groups of elements. These 63 elements—such as lead, nitrogen, or carbon—were substances that couldn’t be broken down into simpler substances. For example, water was thought to be an element in the ancient world, but by passing electricity through water vapor each molecule would break down into two hydrogen atoms and one oxygen atom (H₂O) and neither of these could be reduced further. Many of these elements showed periodicity, or clustering around certain characteristics such as boiling point and atomic weight, suggesting that there was an underlying structure. It was identifying this structure that became Mendeleev’s obsession.

One strange pattern Mendeleev thought required explanation was that when the atomic weight of an element increased so did the number of oxygen atoms that would bond with it. But it wasn’t as simple as increased mass increasing the number of valence bonds. Sodium, for example, had an atomic weight of 23 and a valence of 1, the same as potassium with a weight of 39. But there seemed to be a pattern that occurred in clusters of eight. Increase the atomic weight and the valence would increase with it, until you reached the eighth element where the valence pattern started over again. Armed with careful measurements of atomic weight and experiments on these valence bonds (as well as other periodic patterns) Mendeleev attempted to arrange the elements so that all the known similarities would cluster together. Over a three-day period in February, 1869, working almost nonstop, he constructed an elaborate jigsaw puzzle in which one-third of the pieces were missing and many others were badly misshapen.

Mendeleev's Office, St. Petersburg State University, Photo by Author

However, the key to this periodic law as he called it, was that it made specific predictions. Mendeleev felt confident that there were elements that hadn’t been discovered yet and he intentionally left gaps in his table. He predicted that that there should be additional unidentified elements with atomic weights of about 44, 70, and 72 that would fill the holes in his model. Over the next few years all three hypothetical elements were discovered precisely as he predicted (later to be named scandium, gallium, and germanium). By using a combination of precise measurement and creative insight, Mendeleev had intuited order in the very fabric of reality.

When Anna Petrova first met the man whose life would ultimately collide with her own, he was at the height of his international fame. There was no way she could have known that, at the very moment when Mendeleev’s scientific legacy was firmly established, his personal life was already beginning to unravel.

. . . To Be Continued.