Inferior

by Angela Saini

  Those with the male brain tend to spend hours happily engaged in car or motorbike maintenance, small-plane piloting, sailing, bird- or train-spotting, mathematics, tweaking their sound systems, or busy with computer games and programming, DIY or photography. Those with the female brain tend to prefer to spend their time engaged in coffee mornings or having supper with friends, advising them on relationship problems, or caring for people or pets, or working for volunteer phone-lines listening to depressed, hurt, needy or even suicidal callers.

  It’s a slightly odd list. Peculiarly middle class and English, for one. It’s also difficult not to notice that the male brain appears better suited to higher-paying, higher-status jobs like computer programming or mathematics, while the female brain seems to fit best with lower-status jobs, such as a caregiver or unpaid helpline worker.

  Nonetheless, Baron-Cohen’s ideas have been popular. His paper on the extreme male brain theory of autism has been cited more than a thousand times by other researchers. And the ideas behind empathizing-systemizing theory have been widely mentioned by academics and intellectuals working in child development and gender. The eminent British biologist Lewis Wolpert talks about his work in his own book on sex differences, Why Can’t a Woman Be More Like a Man?, published in 2014. “In general. . .the trend may be summarised as males tending to think narrowly while females think broadly,” writes Wolpert.

  Professor of biology and gender studies at Brown University Anne Fausto-Sterling, however, is wary of research that claims to see sex differences in such young children. It’s a controversial area of science, especially given how unpredictable babies can be. It’s also too easily swallowed by parents looking to understand their kids better, she adds. “You see it on baby websites. You know, ‘Expect your girl to do this, expect your boy to do this.’” When scientists make these claims, argues Fausto-Sterling, they need to be sure their findings are reliable. If Simon Baron-Cohen’s work is taken seriously, his ideas could have important consequences for the way society makes judgments about what men and women should be doing with their lives. “I think you end up having a theory that gives you permission to limit both boys and girls to certain kinds of behaviors or longer term interests, eventually vocations,” she adds.

  Simon Baron-Cohen was always aware that he was wading into divisive territory. He writes near the start of The Essential Difference that he delayed finishing it for years because he thought the topic was too politically sensitive. He makes the defense often made by scientists when they’re publishing work that might be interpreted as sexist—that science shouldn’t shy away from the truth, however uncomfortable it is. It’s a claim that runs all the way through work by people who claim to see sex differences. Objective research, they say, is objective research.

  “A lot of research findings never get replicated and are probably false.”

  When sex hormones were identified at the start of the twentieth century, many scientists assumed they had just a fleeting effect on sexual behavior, the same way we now realize that someone might get an adrenaline rush when they’re stressed or a surge of oxytocin when they’re in love. As research progressed, however, some began to suspect that there might be something more permanent going on.

  In 1980 two American researchers, psychologist and primate expert Robert Goy and neuroscientist Bruce McEwen, published a survey of animal experiments from preceding decades that explored the effects of testosterone levels around the time of birth. One study revealed that female rats given a single injection of testosterone on the day they were born showed less sexual behavior associated with females and more that associated with males when they became adults. Similar results were shown in rhesus monkeys, a species that’s biologically not so far from humans and often used in research. A rhesus monkey was the first mammal sent into space, for instance. The more testosterone the monkeys were given, the more dramatic the differences.

  Goy and McEwen’s book Sexual Differentiation of the Brain claimed that testosterone has a lasting impact on future sexual behavior. But research like theirs couldn’t be divorced from the age in which it was being done. Both science and gender studies had established the enormous role that culture plays in gender identity. In 1980 people commonly assumed that male and female brains were the same, and that behavioral differences in adults must be due to the way people were raised by their parents and shaped by society. One commentator compared talking about fetal testosterone and sex differences in the brain to talking about race and gaps in intelligence.

  In an atmosphere like this, ideas like Goy and McEwen’s marked a radical shift. And of course, they didn’t go unchallenged. Critics pointed out, for instance, the bias in language being used to describe masculinity and femininity. Anything tomboyish, for instance, was interpreted as a girl behaving like a boy. But who was to say that this wasn’t in fact a normal, common feature of being female? Others later complained that theories relying on primate studies for evidence didn’t take into account that monkeys might treat their male and female offspring differently, as humans tend to do. If their genitals were affected by hormone treatment, this might affect how their mothers related to them, which might then have repercussions on their play or sexual behavior as adults.

  Even though not everyone was comfortable with Goy and McEwen’s findings, their line of research continued. It took its biggest leap with the controversial idea that the brain’s entire structure might be shaped by testosterone levels in the womb, making men and women fundamentally different from birth—affecting not just sexual behavior but other behaviors as well.

  Scottish neurologist Peter Behan and the US-based neurologists Norman Geschwind and Albert Galaburda said that studies on rats and rabbits showed how, even before a baby was born, higher than normal levels of testosterone slowed development on the left side of the brain, making the right side more dominant. Extended to humans, since boys naturally have more testosterone exposure before birth than girls do, it followed that men would be the ones who tend to have this larger right half of the brain. Interviewed by a reporter for the journal Science in 1983, Geschwind claimed that, if the mechanism connecting higher than usual levels of testosterone and the way a person responded to it was “just right, you get superior right hemisphere talents, such as artistic, musical or mathematical talent.” It might explain, he implied, the higher numbers of world-class male rather than female composers and artists.

  At the time, there was no medical way of safely measuring testosterone levels in a living fetus. So Geschwind instead relied on studying people who were left-handed (the right half of the brain tends to control muscles on the left side of the body, and vice versa, so someone with a dominant right half would be more likely to be left-handed). By this rough measure, at least one study at the time did indeed show slightly more left-handers among mathematically gifted children compared to the population in general.

  In 1984 Geschwind and Galaburda published a book titled Cerebral Dominance, spelling out how their evidence supported the concept that men’s brains were profoundly steered in a different direction by testosterone. And this is the very research that Simon Baron-Cohen has called upon in developing his own theory about empathizing female brains and systemizing male brains.

  Geschwind died the same year that Cerebral Dominance came out. His death left the lingering question of whether he was right. Did the small amount of evidence in its favor mean that male brains really were hugely shaped by testosterone, or was the truth more complicated? “He was one of the most distinguished of neurologists,” says Chris McManus, a professor of psychology at University College London, who has spent years dissecting the Geschwind-Behan-Galaburda theory. This was part of the problem with his work on testosterone and the brain, he adds. Geschwind’s eminence in his field made it easy for his theory to be published in important journals, even when it turned out that the evidence for it was worryingly thin.

  According to McManus, the Geschwind-Behan-Galaburda theory simply tried to do too mu
ch. At the time, it became a grand theory of how the brain was organized, drawing big connections between things that weren’t necessarily connected, and between which the connections hadn’t been proven. It was so broad that, even to this day, researchers have difficulty pinning it down. “If you’re lucky, you can make it explain anything. . . . You can cut these things any way you want when you float free from data,” says McManus.

  But that doesn’t mean that it was utter hokum.

  Since the 1980s, detailed research using new techniques on animals does seem to suggest that sex hormones affect the brains of fetuses as they develop, leading to small differences in certain behaviors later on. It’s a phenomenon that now has enough evidence behind it that neuroscientists and psychologists feel they cannot ignore it, even if this runs counter to their instincts. This is the unexpected nature of science: findings don’t always sit happily with politics, and results are not always black and white. In this case, even though Geschwind’s grand theory turns out to have been a little too grand, there may have been a kernel of a promising line of research hidden inside it.

  In 2010 Cambridge University psychology professor Melissa Hines, who has carried out some of the world’s most influential studies on sex and gender and is heavily referenced in Baron-Cohen’s own papers, wrote in the journal Trends in Cognitive Sciences that thousands of experimental studies on nonhuman mammals show testosterone levels in the womb really do have an effect on behavior later on. Work like this is done by artificially injecting primates with extra hormones before monitoring their behavior. Her article includes a compelling pair of photographs, one of a female monkey inspecting a doll and the other of a male monkey moving a toy police car along the floor in a way that a child might.

  But then, monkeys and humans are not the same. Making the leap from animals to people is critical to proving whether testosterone really does shape our own complicated minds in the same ways. If there is a similar difference, is it small, as it is in other mammals? Or is it large, in the way that Simon Baron-Cohen at Cambridge University suggests it is in his controversial empathizing-systemizing theory of male and female brains? Where does the truth lie?

  Of course, the ethical standards for doing this research with humans are very different from primates. Scientists can’t artificially inject a fetus or a child with more hormones to study the effects. Instead they must turn to people who have naturally very high or very low sex hormone levels. And these people are rare.

  “I was unfinished when I was born,” says Michael.

  Michael isn’t his real name, which I agree not to use. His real name isn’t even his original name, which was Eilean. Michael’s fifty-first birthday was two days ago, but he tells me he chooses not to celebrate it because he doesn’t want to be reminded of the day he was born. That was the day his parents were told to raise him as a girl.

  Michael was born a man, but a rare genetic condition meant that, at birth, his body didn’t reflect this. Women typically have two sex chromosomes, known as “XX,” and men have two called “XY.” This Y chromosome is crucial because it helps prompt a fetus to produce androgens such as testosterone that make his body become obviously male inside the womb. Genes and hormones working together in this way are what make males look more male and females look more female. Michael is a regular XY male, but he has five-alpha-reductase deficiency, which means he’s missing the enzyme that converts testosterone into a chemical that’s crucial to developing the sex organs before birth. This means that he was genetically male, but his genitalia were ambiguous.

  Cases like Michael’s have helped biologists and psychologists get a grip on what it really means for humans to be born biologically one sex or another. If we want to know how sex hormones influence how masculine or feminine a person is, there’s no better way than to study a person who is genetically male but whose body doesn’t respond to hormones in the same way as the average man.

  “When I was born, my sex wasn’t determined at first look,” he explains. “I had a penis but it was very, very small.” It used to be common in cases like these for doctors to advise people like Michael to live their lives out as girls, because surgery to make their genitals appear female is simpler than constructing a penis. When Michael was born, experts believed that gender was so heavily shaped by society that this was a perfectly reasonable choice to make. If he were treated like a girl, he might feel like one. Some children in similar situations have adapted to their new gender identities. But for many, including Michael, decisions like these have led to personal tragedy.

  His underdeveloped testes were left inside his body, before being partly removed when was five years old, long before puberty set in. This surgery was accidentally left incomplete, which meant that he was still producing small amounts of testosterone. The whole time, he was oblivious to his genetic sex. To the world he was a girl, but inside he became increasingly aware that he didn’t feel like one.

  At around the age of three, he started showing an interest in typical boys’ toys. Later in his school’s physical educational lessons, when girls were told to go to one side of the sports hall and boys to the other, he would stand in the middle, uncertain. “The teachers kept separating me off from the boys,” he remembers. For a young boy, the situation was as tragic as it was confusing. Another time, when a shopkeeper asked him, “What can I get for you, son?” he imagined in delight that she must have seen him for who he truly was. When someone behind him explained that he was actually a girl, it felt like a slap in the face. “As I got older, I looked at my grandmother, and mother, and female cousins and realized I will never be like them,” he recalls.

  His childhood was an impossible confusion, trapped between what society expected of him—including being repeatedly told, “Girls don’t behave like that!”—and his personal conviction that he was a boy. He remembers his shame when, as a member of a choir as a child, his voice began to break and he had no choice but to blame it on a sore throat. When he was much older, people assumed he was just a very athletic girl. “People identified me as a tomboy,” he explains.

  People with conditions like Michael’s are today described as “intersex.” It’s an umbrella under which many extremely rare conditions sit, including androgen insensitivity syndrome, in which a person with male chromosomes appears entirely female because their body doesn’t recognize testosterone, and congenital adrenal hyperplasia, in which women are born looking female but have high levels of male hormones, which can cause ambiguous genitalia. They’re not eunuchs or hermaphrodites. They don’t fit the binary categories of male and female, but instead occupy a biological middle point, which many people have yet to accept or understand.

  “I have seen less than ten cases in my entire career,” says British endocrinologist Richard Quinton of androgen insensitivity syndrome, one condition he treats. A career spent observing people with intersex conditions, along with others who want to change gender, has given Quinton a special insight into how hormones affect sexual identity. Many patients choose to keep quiet about their conditions. But Quinton heard of an instance once in the Middle East where two sisters, both with androgen insensitivity syndrome, brought a case before the Islamic courts to be recognized as men so they could secure their family inheritance, which wouldn’t be passed down to them if they were women. With congenital adrenal hyperplasia, he says, “at the extreme end you can have some births that tend to look male,” although most look female with some masculine features. These patients “are said to be more tomboyish in their behavior, certainly in childhood. And when older, many are also attracted to the same sex.”

  At sixteen years old, after finding out his true medical history, Michael finally had a chance to make his own decision about how to live the rest of his life. At nineteen he began transitioning into a man, taking weekly testosterone injections. His voice got deeper; hair grew on his arms, legs, and face; and he developed more muscle. “It was like the sun coming out,” he says.

  The genital surgery i
nflicted on him when he was born was described at the time as “tidying up,” but he sees it now as child abuse. “What happens with a lot of these children is that they grow up in confusion,” says Michael, who has since found acceptance and understanding through the support group UK Intersex Association.

  Today Michael is a psychologist with a specialty in child mental health, a career he chose partly because of his own experiences. His voice is strong and clear. His gender is indisputably male. He is also living evidence that at least some aspects of gender identity must be rooted in biology. Hormones don’t just affect how our bodies look, but how we perceive ourselves, too. The question this then raises is how much more of an effect do hormones have on how we think and behave? How much do testosterone, estrogen, and progesterone shape our minds and steer them in different directions?

  I’m told that psychology professor Melissa Hines is one of the most balanced and fair researchers in her field—which is important in a field that is sometimes neither balanced nor fair. Her office, at the end of a warren of old, wooden corridors behind a small lane in Cambridge, is lined with books about gender from all sides of the debate. She chooses her words carefully.

  “We’ve looked at a variety of behaviors,” she begins. Hines relies on intersex cases like Michael’s to carry out her research on the effects that hormones have on psychological sex difference, including intelligence. Like baby research, this is an important part of the equation when it comes to understanding nature and nurture. If testosterone does steer boys toward having a distinctly male brain, different from a female brain, then we should see clear differences in how people with unusually high or low testosterone behave.

  Her findings reveal three areas that show a statistically marked difference. Starting with the obvious first, “for gender identity, the differences are huge. Most men think of themselves as men and most women don’t,” she states. “The second thing is sexual orientation. Most women are interested in men, and most men aren’t.” The third one is childhood play behavior. Studying girls with congenital adrenal hyperplasia, with higher than normal levels of testosterone, she found, “Rough-and-tumble play is increased in girls exposed to androgens. They like boys’ toys a bit more, girls’ toys a bit less, and they like to play with boys more than the average girl does, but not as much as the average boy. That’s been replicated by seven or eight independent research teams.”