Inferior

by Angela Saini

  At the start of 2013 the US Food and Drug Administration took the landmark decision to lower the recommended starting dose of Ambien, halving it for women. “Zolpidem is kind of like a signal case,” says Arthur Arnold.

  However, just as with digoxin, the finding needed to be unpacked a little further. In 2014 research exploring the effects of zolpidem, carried out by scientists at Tufts University School of Medicine, suggested that its lingering effect may be mostly due to women’s lower average body weight compared to men, which means the drug clears from their systems more slowly.

  Digoxin and zolpidem highlight the pitfalls of including sex as a variable in medical research. Besides average body weight and height, women also have on average a higher percentage of body fat than men. And they generally take longer to pass food through their bowels. Both are things that might affect how drugs behave in their bodies. But they are also factors on which men and women overlap. Many women are heavier than the average man, for instance. It’s not always the case that the sexes belong in two separate categories.

  What also counts is the experience of being a woman, socially, culturally, and environmentally. “Both sex and gender are important factors for health,” reminds Janine Clayton. Ideally, then, people should be treated according to the spectrum of factors that set them apart. Not just sex, but also social difference, culture, income, age, and others. As Sarah Richardson has written, “A female rat—not to mention a cell line—is not an embodied woman living in a richly textured social world.”

  The problem is that “medicine is very binary. Either you get the drug or you don’t. Either you do this or you do that,” says Sabine Oertelt-Prigione, who supports gender-based medicine. “So the only step, I believe, is to incorporate the notion that there is actually not one neutral body, but at least two. I believe it’s just another way of looking at things. In medicine, just having a way to change paradigms and look at things differently can open up whole arrays of possibilities. It could be looking at sex differences, but there are many other things that could help to make health care more inclusive in the end.”

  “What are we trying to do? We’re trying to improve human health, right?” adds Kathryn Sandberg. “So if we see a disease is more prevalent or more aggressive in men than women, or vice versa, we can learn a lot about that disease by studying why one sex is more susceptible while the other is more resilient. And this information can lead to new treatments that benefit all of us.” Understanding why women tend to live longer could help men live longer. Including pregnant women in research may open up the cabinet of drugs that doctors can’t currently prescribe because their effects on fetuses are uncertain. Medical dosages might be affected by a better understanding of how a woman’s body responds across her menstrual cycle.

  At the moment at least, the verdict of politicians and scientists seems to be that including sex as a variable when carrying out medical research can improve overall health. In 1993 the US Congress introduced the National Institutes of Health Revitalization Act, which includes a general requirement for all NIH-funded clinical studies to include women as test subjects, unless they have a good reason not to. By 2014, according to a report in Nature by Janine Clayton, just over half of clinical-research participants funded by the NIH were women.

  Since the start of 2016 the law in the United States has been broadened to include females in vertebrate animal and tissue experiments. The European Union now also requires the researchers it funds to consider gender as part of their work.

  For women’s health campaigners and researchers like Janine Clayton and Sabine Oertelt-Prigione, this is a victory. To have females equally represented in research is something they’ve spent decades fighting for. Male bias, where it exists, is being swept away. Women are being taken into account. Maybe we will finally understand just what it is that makes women on average better survivors and why men seem to report less sickness.

  But as science enters this new era, scientists need to be careful. Research into sex differences has an ugly and dangerous history. As the examples of digoxin and zolpidem prove, it’s still prone to errors and overspeculation. As much as it can improve understanding, it also has the potential to damage the way we see women and drive the sexes farther apart. The research into genetic sex differences by people like Arthur Arnold doesn’t just affect medicine but also how we see ourselves.

  Once we start to assume that women have fundamentally different bodies from men, this quickly raises the question of how far the gaps stretch. Do sex chromosomes affect not just our health but all aspects of our bodies and minds, for example? If every cell is affected by sex, does that include brain cells? Do estrogen and progesterone not just prepare a woman for pregnancy and boost her immunity but also creep into her brain, affecting how she thinks and behaves? And does this mean that gender stereotypes, such as baby girls preferring dolls and the color pink, are in fact rooted in biology?

  Before we know it we land on one of the most controversial questions in science: Are we born not just physically different but thinking differently too?

  CHAPTER 3

  A Difference at Birth

  Girls and boys, in short, would play harmlessly together, if the distinction of sex was not inculcated long before nature makes any difference.

  —Mary Wollstonecraft,

  A Vindication of the Rights of Woman, 1792

  “We live in jeans, don’t we? They go with everything!” coos the mother. Her six-month-old daughter is wearing the tiniest pair of jeans I’ve ever seen, and she herself is dressed head to foot in denim.

  We’re sitting together in the baby lab at Birkbeck College in central London. It reminds me of a nursery, but a somewhat unusual one. A purple elephant decorates the door to a waiting area full of toys. Downstairs, meanwhile, a baby might be hooked up to an electroencephalograph that monitors her brain’s electrical activity while she watches pictures on a screen. In another room, scientists could be watching a toddler play, examining which toys he happens to choose. Meanwhile, in this small laboratory that I’ve been invited into, a baby is being gently stroked along her back with a paintbrush. She’s the thirtieth infant to be studied so far in this experiment.

  “She really just likes sitting and watching, taking it all in. I’m happy sitting and observing, myself,” her mother continues, bouncing the girl on her knee. Researchers suspect that human touch like this has an important impact on development in the early years. They just don’t know how or why. So the goal of today’s experiment is to measure how touch affects a baby’s cognitive development. It’s one of countless ways in which children are affected by their upbringing, slowly shaped into the people they will become.

  Cute though babies are, studying them this way is not as much fun as it might seem. It’s almost like working with animals. The challenge is to come up with clever experiments that get to the heart of their behavior without accidentally reading too much into what an infant does. A stare can be meaningful or mindless, while even the most charming a smile may just be wind. In this case, the researchers are using a paintbrush to run their touch experiment because that’s the only way to control for parents stroking their children in different ways. With a brush, you can be sure it’s the same every time.

  Unfortunately, the baby’s bottom lip begins to quiver and she erupts into tears. It’s clear the paintbrush doesn’t measure up to real touch. This is one result that can’t be used.

  “This is what baby science is. Trying to get a signal out of the noise,” laughs Teodora Gliga, a psychologist at Birkbeck’s Centre for Brain and Cognitive Development, who carries out research in the baby lab. Gliga’s work focuses on how children develop in their early years, in the tradition of the Swiss psychologist Jean Piaget who, from the early twentieth century, observed his own children and famously realized that many of the assumptions scientists had made about early development were wrong. Babies aren’t blank slates. Instead, he believed they are preprogrammed with their own ways of organi
zing knowledge about the world. The simplest example of this is a newborn’s instinctive reflex to suck.

  But this is just the start, scientists are realizing. The aim now is to figure out exactly how smart children are at birth, and what this means. One other use of baby research is to investigate differences between boys and girls. If children really are preprogrammed in some way, is the programming different depending on the sex? Do little girls prefer dolls dressed in pink because they’re female or because society has taught them they should prefer dolls and the color pink?

  Plenty of research has already been done. We know that around the age of two or three, children start to become aware of their own sex. Between the ages of four and six, a boy will realize that he will grow up to be a man and a girl that she will be a woman. It’s also by then that children have some understanding of what’s appropriate for each gender according to the culture they’re in. American psychologist Diane Ruble and gender development expert Carol Lynn Martin have explained how, by the age of five, children already have in their heads a constellation of gender stereotypes. They describe one experiment in which children were shown pictures of people doing things like sewing and cooking. When a picture contradicted a traditional stereotype, the kids were more likely to remember it incorrectly. In one instance, instead of remembering that they had seen a picture of a girl sawing wood—which they had—some said instead that they’d seen one of a boy sawing wood.

  Some parents are acutely aware of the problem. The mother of the baby I’m observing in the lab today tells me that she’s a researcher with a PhD and she would like her daughter to have a PhD one day, too. Along the way, she’s trying to avoid exposing her to gender stereotypes that might harm her sense of what she’s able to do. “I’m not averse to pink, but we’ve tended to buy navy and blue things,” she tells me. Someone offered to sell her a dolls’ house recently, but she refused to take it. “I’d rather have something more neutral,” she adds.

  Researchers like those at Birkbeck College have realized that one of the most effective ways for scientists to sift nature from nurture, the biological from the social, is by studying children so young that they haven’t yet been exposed to society’s heavily gendered ways. “I don’t think that studying adults tells us anything about sex differences. It tells us something about the lives those people lived. It’s more about their experiences than about the biology of it,” explains Teodora Gliga.

  “The earlier you go in development, the closer you are to nature.”

  In 2000 a brief scientific article was published in the international journal Infant Behavior and Development describing an experiment that would shape the way people around the world thought about sex differences at birth. It was written by a team from the Departments of Experimental Psychology and Psychiatry at Cambridge University, which included Simon Baron-Cohen, a psychologist, neuroscientist, and famous expert on the medical condition autism. The paper claimed to prove for the first time that there were noticeable and important sex differences in the way newborn babies behaved.

  The results were so powerful that they’ve been cited at least three hundred times in other research papers, as well as in books about pregnancy and childhood. When the then president of Harvard University, Lawrence Summers, controversially suggested in 2005 that the shortfall of female scientists and mathematicians might be because of innate biological differences between women and men, Simon Baron-Cohen used this study to defend him. Harvard University cognitive scientist Steven Pinker and London School of Economics philosopher Helena Cronin have both deployed it to argue that innate differences between the sexes exist. It has even made it into a Bibleinspired self-help book, His Brain, Her Brain, about how “divinely designed differences” between the sexes can help strengthen a marriage.

  Since 2000, Baron-Cohen’s department has made a formidable name for itself. At the time his paper was published, he was just two years away from unveiling a controversial and wide-ranging new theory about men and women, which he has named empathizing-systemizing theory. Its basic message is that the “female” brain is hardwired for empathy, while the “male” brain is built for analyzing and building systems, like cars and computers. People may show varying degrees of maleness and femaleness in their brains, but as the adjectives helpfully suggest, men on average tend to have “male” brains while women tend to have “female” ones.

  Autism, which makes it difficult for people to understand and relate to others, is an extreme version of the male brain, adds Baron-Cohen. This is why people diagnosed with autism (until a few decades ago, they were almost all men, but many more women are now being identified with the condition, too) sometimes show unusual systemizing behavior, like the ability to do mathematical calculations in their heads very quickly or to memorize train timetables.

  As yet, no one has been able to fully explain how, at the very start of a child’s life, its brain gets set on a path toward being more male or more female. If such a mechanism is at work, the details are likely to be complicated. But according to Baron-Cohen, the crucial element is sex hormones—the chemicals at the root of many of the physical differences we see between women and men. Testosterone exposure in the womb, he argues, doesn’t affect just the gonads and genitals but somehow also seeps into the male fetus’s developing brain, molding it into a systemizing male brain. Female fetuses, which tend not to have as much testosterone, are left by default with empathizing female brains.

  So then, what was the significance of his paper on newborn babies? Baron-Cohen wanted to see whether the stereotypes of women having stronger social skills and men being more mechanically minded might have a biological basis—in other words, whether girls are born empathizers and boys are born systemizers. For the first time anywhere, as far as he and his team were aware, they convinced the maternity ward of a local hospital to allow them to run a study on the youngest possible group of people. More than a hundred babies were included in the study, all around two days or younger, and all clearly far too young to be affected by social conditioning. What they would observe, they claimed, would be nature untainted by nurture. And this made it a vitally important piece of evidence on which his empathizing-systemizing theory would hang.

  Like many senior scientists do, Baron-Cohen left the experiment itself to a junior colleague, who had just joined his team. Jennifer Connellan was a twenty-two-year-old American postgraduate student. “I can’t believe he accepted me into his lab actually,” she tells me. By her own admission, she was young and inexperienced. Before arriving at Cambridge she was lifeguarding on a beach in California.

  Each day, Connellan would turn up to the maternity ward to see if any mothers had given birth. The experiment itself was simple. “We wanted to contrast social versus mechanical,” she says. So every baby was shown a face, which happened to be Connellan’s own, and a mechanical mobile made from a picture of Connellan’s face. They then measured how long every child looked at each one, if they looked at all. This long-established experimental method in baby research is known as “preferential looking.” More socially inclined babies, the researchers hypothesized, would prefer to stare at the face, while more mechanically inclined babies might choose to look at the mobile. “It was quite rudimentary as far as the design,” she recalls. “I felt like it was kind of like a science fair project.”

  When the results came in, a large proportion of babies showed no preference for the face or the mobile. But around 40 percent of the baby boys preferred to look at the mobile, compared to a quarter who preferred the face. Meanwhile, around 36 percent of the baby girls preferred the face, while only 17 percent preferred the mobile. It certainly wasn’t the case that every boy was different from every girl, but, in research terms, the difference was statistically significant, enough for the scientific community to take notice.

  In the published paper, Jennifer Connellan, Simon Baron-Cohen, and their colleagues argued that this was overwhelming evidence that boys are born with a stronger interest in mec
hanical objects, while girls tend to have naturally better social skills and more emotional sensitivity. “Here we demonstrate beyond reasonable doubt that these differences are, in part, biological in origin,” they wrote.

  “We were surprised that it was significant, that there was a significant difference,” Connellan remembers. “[Baron-Cohen] was excited. I would say both of us were. We spent a lot of time going through it, making sure the results were what we thought they were.” And sure enough, there it was, some of the seemingly strongest evidence yet that boys and girls really are born different. Cultural stereotypes about women being more empathic and men being more interested in building things might not just be due to the way their parents raised them and how society treated them.

  “The fact that this was the earliest gender difference, that part was almost, like, shocking,” she tells me.

  The next few years saw Simon Baron-Cohen put more meat on the bones of his idea that there are such things as distinctly female and male brains.

  In 2003 he published The Essential Difference, a book written for the general public that lays bare what he sees as fundamental gaps between how men and women think. It includes a description of Connellan’s experiment, along with pictures of her face and the mobile she showed the babies. “This sex difference in social interest was on the first day of life,” he writes, adding elsewhere: “This difference at birth echoes a pattern we have seen right across the human lifespan. For example, on average, women engage in more ‘consistent’ social smiling.” The clear implication is that the sexes don’t appear to behave differently because of society or culture, but because of something profoundly innate and biological.

  The differences, Baron-Cohen explains in his book, can be spotted in the types of hobbies people tend to choose.