Inferior

by Angela Saini

  Researchers rarely look at the brain in this way. Very often they’re studying just one brain region, like the amygdala or hippocampus, or one particular behavior, like mathematical ability or watching porn. Looking at the brain and behavior as a whole produces very different results when it comes to sex difference. Joel’s research reveals that, depending on the study, between 23 and 53 percent of people show variability in their brains, with features associated with both men and women. Meanwhile, the proportion of people in the studies she has analyzed that have purely masculine or purely feminine brain features is between none and 8 percent.

  “If you take any two brains, they are different, but how they differ between any two individuals, you cannot predict,” she explains. By this logic, there can’t be any such thing as an average male or average female brain. We are all, each one of us, a mix. Our brains are intersex.

  Having the fresh perspective of female researchers like Gina Rippon, Anne Fausto-Sterling, Melissa Hines, Cordelia Fine, and Daphna Joel—while it may not immediately change how science tackles sex difference—may at least force a rethink of old beliefs that women’s minds must be essentially different from men’s because the only alternative would be that they’re identical. They take the black and white divisions of the past and reveal that the truth is more likely to be gray.

  Anne Jaap Jacobson, a philosopher and emeritus professor at the University of California, Berkeley, now based at the University of Houston, has coined the word neurofeminism to describe this alternative approach to brain science, which attempts to root out stereotypes and look at brains objectively. “A lot of the research starts off with the assumption that various people call ‘essentialism.’ That men and women are essentially different, that the differences are really sort of basic,” she tells me.

  “The problem with this question of difference and similarity is that we’re all different and we’re all similar,” explains Daphna Joel. “When people want to study sex in the brain, they immediately translate this to studying sex differences. But already here they make many assumptions, and the first is that there are two populations of brains, male and female. This is an assumption that needs to be shown scientifically, or proven. They say: ‘This is solid ground, and from here I continue.’ I question the solid ground.”

  Neuroscientist Paul Matthews agrees that this approach could be a useful corrective for neuroscience. “Comparing males and females at any one time point is a complicated question to make meaningful, because it is actually so ill-defined as posed,” he says. “There’s a lot of variability in individual brains. In fact, the anatomical variability is much greater than we ever realized before. So the notion that all people of the male sex have a brain that has fixed characteristics that are invariant seems less likely to me. In fact, so much less likely that I think the notion of trying to characterize parts of the brain as more male-like or more female-like actually isn’t useful.”

  Ruben Gur, while he refuses to shift in his conviction that sex differences in the brain are the rule rather than the exception, admits to me that these days he has changed the language he uses. “A lot of people are using the term ‘sexual dimorphism’ when they talk about sex differences in brain structure, and I’m guilty of that myself,” he says. “I’ve done that, but I don’t do that anymore. Because if you think of it, when you talk about dimorphism, you’re really talking about sexual dimorphism. You’re talking about different forms. So a penis versus the vagina, that’s a sexual dimorphism. Having breasts is a dimorphism. I wouldn’t go so far as saying the brain is dimorphic. I would say there are some significant differences, sex differences, in brain anatomy, but I wouldn’t say they rise to the level of being dimorphic.”

  All this work on sex difference in our bodies and brains has a story underneath it.

  When neuroscientists like Ruben Gur and Simon Baron-Cohen claim to see profound gaps between women and men, they are aware that these gaps aren’t spontaneous. If they’re there, they’re there for a reason. Gur has described them as revealing how we are “built to complement each other,” suggesting that humans must have evolved with some sexual division of labor between them. Women, he implies, are the more empathic, intuitive sex, perhaps built for parenting. Men are better at seeing and doing, he says, which seems to suggest they are the natural hunters and builders. Baron-Cohen also argues that men tend to be the systemizers while women are the empathizers.

  “If your job is to lift a hundred and fifty pounds, and you can’t do it, why should you want to work in that job?” Gur asks me.

  It’s hard to argue with that kind of logic. But while he’s willing to speculate on what biology tells us women have evolved to be able to do, it’s a question that’s beyond his job description. It belongs to the field of evolutionary biology.

  The evolutionary perspective reminds us that our bodies weren’t created yesterday. They were forged over millennia, every part slowly adapting to the pressures of the environment to better serve some need. From breasts and vaginas to brain structure and cognitive ability, for every difference or similarity we see, there must be some evolutionary purpose to it. This is where the sex differences and similarities that biologists claim to see in our bodies and brains connect with the story of our past. If women are better survivors than men, the explanation for it is in this tale. If women and men have quite similar brains, the reasons for that are here, too.

  Evolutionary biologists have the almost impossible task of deciphering this story. Did the sexes complement each other, the way Ruben Gur suggests, or did they do the same jobs and share parenting? Were women crouched around a campfire, tending to children and waiting for male hunters to bring home the bacon? Were they independent, hunting for their own food? Were they monogamous or promiscuous? Were males always dominant over females?

  They are questions that science may never fully answer, but there are ways to try. One window on the past is provided by primatologists studying our closest animal cousins, the great apes, from whom humans split around five million years ago. Studying how they interact gives us some insight into what our basic way of life may have been before we became the species we are now. Another window comes from evolutionary psychologists, who try to picture life in the Pleistocene, the epoch during which modern humans evolved looking anatomically the way we do now. Then there’s archaeological evidence, such as tools and bones. By observing the lives of modern-day hunter-gatherers, anthropologists can also draw portraits of how early woman might have lived.

  Writing our evolutionary story isn’t easy and it’s also plagued by controversy. As Charles Darwin’s work in the nineteenth century proves, the narratives have often been shaped by the attitudes of the time. Even he, the father of evolutionary biology, was so affected by a culture of sexism that he believed women to be the intellectually inferior sex. It’s taken a century for researchers to overturn these old ideas and attempt to rewrite this flawed tale.

  CHAPTER 5

  Women’s Work

  We still live in a world in which a significant fraction of people, including women, believe that a woman belongs and wants to belong exclusively in the home; that a woman should not aspire to achieve more than her male counterparts.

  —Rosalyn Sussman Yalow, in her banquet speech on being awarded the Nobel Prize in Physiology or Medicine, December 1977

  The long road to the sprawling home of Sarah Blaffer Hrdy, primatologist, anthropologist, and emeritus professor at the University of California, Davis, is flanked by dry fields. She and her husband carved their walnut farm here, near Sacramento, out of almost nothing. The trees are new, the pastures on which their lambs and goats are feeding are new, and they planted the spindly silver walnut groves themselves. She survives under the looming possibility that wildfires could come along to claim it all, as they’ve almost done in the past.

  But then any fire would have to battle Hrdy herself, who, now seventy years of age, is a force of nature in her own right. Hrdy’s work into what primat
e behavior can tell us about human evolution, one scientist tells me, reduced her to tears. For Hrdy’s groundbreaking ideas on women, she’s been described as the original Darwinian feminist.

  Primatology is today a female-dominated field, guided by early pioneers like Jane Goodall and Dian Fossey. But when Hrdy started her career in the 1970s, not only did men rule the roost, the accepted wisdom was that human evolution had been shaped largely by male behavior. Males were the ones under pressure to attract as many mates as possible to increase their odds of having more offspring, males were aggressive and competitive in their quest for dominance, and males needed to be creative and intelligent when they hunted for meat.

  As our closest evolutionary cousins, primates were naturally expected to follow similar patterns. When male primatologists went into the field, they would often focus on aggression, dominance, and hunting, Hrdy tells me. Females were routinely overlooked. They were believed to be passive, sexually coy, and generally at the mercy of stronger, larger males. Indeed, early studies of chimpanzees—a species in which males happen to be particularly aggressive and dominant—reinforced this.

  Things changed for Hrdy when she went out into the field for herself. She finally saw how this account of females might be wrong.

  It began with a trip to Mount Abu, a region of Rajasthan, northwestern India, which is home to a species of monkey known as the Hanuman langur. Hanuman is the name of the Hindu monkey god, a symbol of strength and loyalty, while “the name langur is Sanskrit for having a very long tail,” she explains to me in her large office, which is decorated with framed drawings of primates. “They are the beautiful, elegant gray ones with the black gloves and faces.” Hrdy had heard that male langurs were killing infants of their own species. It was so strange a phenomenon that scientists assumed there must be something desperately wrong with them. Animals simply didn’t behave in ways that were bad for their group, they thought. The only possible cause must be that the male monkeys had gone mad. Overcrowding had created a pathological hotbed of aggression, perhaps.

  The truth was stranger. When Hrdy watched closely, she began to realize the murders weren’t random acts of madness at all. In the everyday course of life, she noticed that male langurs were far from violent toward infants. “I would see young langurs jumping on a male langur reclining on the ground as if he were a trampoline. He was completely tolerant of the infants in his troop. There was nothing pathological about it,” she explains.

  The rare infanticides turned out instead to be carefully calculated. And they were committed by males from outside the breeding group. “When I first did see infants missing, and then later I actually saw a male attack infants, it was very goal-directed stalking, as if by a shark. Day after day, hour after hour.” What was making a male commit this gruesome killing was the expectation that, without her baby, a mother would have to mate again. If he didn’t kill the infant, he would have to wait a year before she finished nursing and started ovulating. She couldn’t mate any sooner.

  To scientists, the idea was shocking. Hrdy had shown that a monkey could choose to kill a healthy young member of his own species simply to perpetuate his bloodline. Infanticide went on to become a fruitful area for animal research. The behavioral patterns Hrdy saw, detailed in her 1977 book, The Langurs of Abu: Female and Male Strategies of Reproduction, have since been reported for more than fifty primate species as well as other animals.

  But something else also fascinated her about these murders. It was the extraordinary way the female Hanuman langurs reacted. They weren’t passive. They didn’t carelessly allow their infants to be killed by aggressive males. Instead, they banded together and put up fights to fend them off. This observation, too, challenged long-standing ideas about natural primate behavior. It showed that females weren’t only fiercely protective of their children (which might have been expected), but that they could also be aggressive and cooperative.

  Questioning assumptions can have a remarkable ripple effect. Further work by Hrdy showed that female langurs were promiscuous, too, contrary to popular wisdom about females being sexually coy. Male langurs, she noticed, attacked only those infants being carried by an unfamiliar female—never by a female with which they’d mated. By having as many mates as possible, Hrdy suggested that female langurs might be strategically lowering the odds of a male killing her infant.

  It became impossible for primatologists to ignore females any longer.

  Hrdy believes that being a woman in her field is one reason she noticed behavior that hadn’t been recognized before. She was driven to investigate what others may have chosen to overlook. “When a langur female would leave her group, or when she would solicit a male when she was pregnant, a male observer may say, ‘Well, that’s just freak,’ and not even follow her to find out where she was going or what she was doing. A woman observer might empathize more with the situation or be more curious.”

  Her work didn’t just mark a sea change in how primates were beginning to be understood but was a personal revelation as well. Hrdy had been raised in a conservative, patriarchal family in south Texas. Noticing how competitive and sexually assertive females could be in the rest of the primate world prompted her to question why women in her own society should be thought of as any different. Primates, particularly great apes such as chimpanzees, bonobos, gorillas, and orangutans, have long been used by science as a way of understanding our own evolutionary origins. We share roughly 99 percent of our genomes with chimpanzees and bonobos. In genetic terms, we are so close that primatologists routinely refer to humans as another great ape. So if other female primates could show so much variation in their behavior, why did evolutionary biologists still characterize women as the naturally gentler, more passive, and submissive sex?

  Trying to get her male colleagues to see primates from a female’s perspective, though, was a battle. When Hrdy returned from her fieldwork in Mount Abu in the 1970s, despite social change happening around her, including a resurgence in feminism, science was still very much a boys’ club. One time at a conference, when she was asked to define what feminism meant to her, Hrdy recalls saying, “A feminist is just someone who advocates equal opportunities for both sexes. In other words, it’s being democratic. And we’re all feminists, or you should be ashamed not to be.” But equal opportunities weren’t always encouraged, in her field at least. Her work, as well as that of many other women scientists, was sometimes treated differently from that of her male counterparts. Some people refused to acknowledge her research, let alone incorporate its ideas.

  Hrdy used to get together with other female researchers at womenonly house parties to discuss the problems they faced. They euphemistically called them their “broad discussions.” And there was plenty to discuss. The influential evolutionary biologist Robert Trivers, a colleague of Hrdy’s, once told a reporter that Hrdy should concentrate on being a mother instead of on her work She forgives him now, she tells me. (Trivers, meanwhile, tells me that he intended the remark to be a secret, and admits he’s sorry it was made public.)

  Exasperated, she even used her work on apes and monkeys to make covert remarks about her male colleagues. “I was writing about how male baboons were the basis of social organization. Males compete with males, and then the dominant males form alliances with each other so as to improve their access to females. And then I would make these very oblique parallels to what went on in American universities,” she remembers. “I was, of course, referring to male professors who, when called out for sleeping with academic subordinates, would back one another up. All through my career, these things were going on.”

  Hrdy’s feminism and science met in the middle, not just because of the behavior of some men in her field but also because she recognized that scientific theories that ignored female behavior were incomplete. “In science, paying equal attention to selection pressure on both males and females, that’s just good science. That’s just good evolutionary theory,” she tells me. One of the most important frontiers,
as she saw it, was understanding mothers and how they defined a woman’s role in human evolution. It was a question that would also lead her back again to the dark phenomenon of infanticide.

  “Cooperative breeding in humans is becoming more and more important.”

  I’m in the ape enclosure at San Diego Zoo, one of the biggest zoos in the world.

  I’m transfixed by a fluffy two-year-old bonobo. She’s cheerfully hanging on to her mother’s fur as the ape leaps from branch to floor, letting go of her to playfully roll on the ground for a few seconds before quickly returning. I have a two-year-old as well. And the bonobos’ behavior reminds me of my own close relationship with my son. In the little bonobo I see a similar mischievousness and even the hint in her of his cheeky smile. They watch each other the same way that we do. The similarities between us are uncanny.

  At close quarters like this, I start to understand why humans are sometimes regarded as another great ape, alongside bonobos, chimpanzees, gorillas, and orangutans. But as much as we have in common, there’s one important contrast between me and the bonobo mother. In the entire time I’m looking into the glass enclosure, I never see her lose contact with her infant. At no point does the little one fall out of her mother’s protectively tight orbit. My son, on the other hand, is already at the other end of the enormous zoo with his father.

  Human motherhood is rarely the single-handed job that it is for chimpanzees and bonobos. Of course, this is something most of us know from our own experience as children or parents. When I’m at home in London, my son typically spends half the week being cared for by other people, including his father, grandmother, and nursery staff. Aunts, uncles, and friends step in too, sometimes. When I’m traveling for work, I go days without seeing him. This isn’t unusual. Few babies or toddlers get through their early years without ever leaving their mothers’ sides.