For my boys, Mukul and Aneurin CONTENTS Introduction CHAPTER 1 Woman’s Inferiority to Man CHAPTER 2 Females Get Sicker but Males Die Quicker CHAPTER 3 A Difference at Birth CHAPTER 4 The Missing Five Ounces of the Female Brain CHAPTER 5 Women’s Work CHAPTER 6 Choosy, Not Chaste CHAPTER 7 Why Men Dominate CHAPTER 8 The Old Women Who Wouldn’t Die Afterword Acknowledgments References Index INTRODUCTION For centuries, scientists have influenced decision makers on important issues including abortion rights, granting women the vote, and how schools educate us. They have shaped how we think about our minds and bodies and our relationships with each other. And of course, we trust scientists to give us the objective facts. We believe that what science offers us is a story free from prejudice. It is the story of us, starting from the very dawn of evolution. Yet when it comes to women, so much of this story is wrong. I was watching a homemade rocket zoom high into the sky. It was a sunny Saturday afternoon and I must have been about sixteen years old, on the playing field of my school in southeast London. Fresh from the nerdy triumph of having been elected chair of the school’s first science society, I’d organized a day building small model rockets before shooting them into the air. I couldn’t think of anything better. The night before, I desperately calculated whether we even had enough construction materials for the crowds that were sure to come. I shouldn’t have worried. On the day, I was the only one who turned up. My chemistry teacher Mr. Easterbrook, a kind man, stayed and helped anyway. If you were the geek growing up, you’ll recognize how lonely it can be. If you were the female geek, you’ll know it’s far lonelier. By the time I reached my final years of school, I was the only girl in my chemistry class of eight students. I was the only girl in my mathematics class of about a dozen. And when I decided to study engineering at university, I found myself the only woman in a class of nine. Things haven’t changed much since then. Statistics collected by the Women’s Engineering Society in 2016 show that only 9 percent of the engineering workforce in the United Kingdom is female and just over 15 percent of engineering undergraduates are women. Figures from WISE, a campaign in the United Kingdom to promote women in science, engineering, and technology, reveal that in 2015 women made up a little more than 14 percent of their workplaces overall. The picture is similar in the United States: according to the National Science Foundation, although women make up nearly half the scientific workforce, they’re underrepresented in engineering, physics, and mathematics. Standing on that playing field by myself at age sixteen, I couldn’t figure it out. I belonged to a household of three sisters, all brilliant at math. Girls stood among boys as the highest achievers at my school. According to the Women’s Engineering Society, there’s little gender difference in enrollment and achievement in the core science and math subjects at secondary level in UK schools. In fact, girls are now more likely than boys to get the highest grades in these subjects. In the United States, women have earned around half of all undergraduate science and engineering degrees since as far back as the late 1990s. Yet, as they grow older, fewer women seem to stick with science. At the top, they’re in an obvious minority. And this is a pattern that runs as far back as anyone can remember. Between 1901 and 2015, 822 men were awarded a Nobel Prize and only forty-eight women. Of these, sixteen women won the Peace Prize and fourteen won the Prize for Literature. The Fields medal, the world’s greatest honor in mathematics, has been won by a woman only once, in 2014 by the Iranian-born mathematician Maryam Mirzakhani. A couple of years after I graduated from university, in January 2005, the president of Harvard University, economist Lawrence Summers, gave voice to one controversial explanation for this gap. At a private conference he suggested that “the unfortunate truth” behind why there are so few top women scientists at elite universities might in some part have to do with “issues of intrinsic aptitude,” that a biological difference exists between women and men. A few academics defended him but, by and large, Summers was met by public outrage. Within a year he announced his resignation as president. But there have always been gently whispered doubts. Summers may have dared to say it, but how many people haven’t thought the same? That there might be an innate, essential difference between the sexes that sets us apart? That the female brain is fundamentally distinct from the male brain, explaining why we see so few women in the top jobs in science? That hushed uncertainty is what lies at the heart of this book. It’s the question mark hanging over us, raising the possibility that women are destined never to achieve parity with men because their bodies and minds simply aren’t capable of it. Even today, we live in the balance of that question, feeding our babies fantasies in pink and blue with the assumption they are deeply different. We buy trucks for our boys and dolls for our girls, and delight when they love them. These early divisions reflect our belief that there’s a string of biological differences between the sexes, which perhaps shape us for different roles in society. Our relationships are guided by the notion, fed by many decades of scientific research, that men are more promiscuous and women are monogamous. Even our visions of the past are loaded with these myths. When we picture early humans, we imagine powerful men wandering out into the wilderness to hunt for food, while softer, gentler women stay back, tending fires and caring for children. We go so far as to wonder whether men may be the naturally dominant sex because they’re physically bigger and stronger. Only science has the power to resolve this dark, niggling feeling that never seems to go away no matter how much equality legislation is passed: the feeling that we aren’t the same, that, in fact, our biology might explain the sexual inequality that has existed, and continues to exist, across the world. This is dangerous territory, for obvious reasons. Feminists in particular have passionately argued against the notion that our biology should determine how we live. Many believe that what science says shouldn’t make a dent in the battle for basic rights. We deserve an equal playing field, they say, and they’re right. But whether or not it sits easily with us, we can’t ignore biology either. If biological differences exist, we can’t help but want to know. More than that, if we want to build a fairer society, we need to be able to understand these gaps and accommodate them. The problem is that answers in science aren’t everything they seem. When we turn to scientists for resolution, we assume they will be neutral. We think the scientific method can’t be biased or loaded against women. But we’re wrong. The puzzle of why there are so few women in the sciences is crucial to understanding why, not because it tells us something about what women are capable of but because it explains why science has failed to rid us of the gender stereotypes and dangerous myths we’ve been laboring under for centuries. Women are so grossly underrepresented in modern science because, for most of history, they were treated as intellectual inferiors and deliberately excluded from it. It should come as no surprise, then, that this same scientific establishment has also painted a distorted picture of the female sex. This, in turn again, has skewed how science looks and what it says even now. When I stood on my own on that playing field as a girl, shooting rockets into the air, I was in love with science. I thought it was a world of clear answers, untainted by subjectivity or prejudice. It was a beacon of rationality free from bias. What I didn’t yet understand was that I found myself alone because it’s not. If you want to know what science tells us about the female of our species, there’s no better place to begin than by understanding the experiences of women working in science today. UNESCO, the United Nations Educational, Scientific and Cultural Organization, which keeps global figures on women in science, estimates that in 2013 just a little more than a quarter of all researchers in the world were women. In North America and Western Europe, female researchers were 32 percent of the population. In Ethiopia, the proportion of female researchers was only 13 percent. The common trend is for women to be around in high numbers at the undergraduate level but to thin out as they move up the ranks. This is best explained by the perennial problem of child care, which lifts women out of their jobs at precisely the moment their male colleagues are putting in more hours and being promoted. When researchers Mary Ann Mason, Nicholas Wolfinger, and Marc Goulden published a book on this subject in 2013, titled Do Babies Matter: Gender and Family in the Ivory Tower, they found that married mothers of young children in the United States were a third less likely to receive tenure- track jobs than married fathers of young children. This isn’t a matter of women being less talented. Unmarried, childless women are 4 percent more likely to get these jobs than unmarried, childless men. The US Bureau of Labor Statistics runs an annual Time Use Survey to pick apart how people spend their hours. Women now make up almost half the labor force, yet in 2014 the bureau found that women spent about half an hour more every day than men doing household work. On an average day, a fifth of men did housework, compared with nearly half of women. In households with children under the age of six, men spent less than half as much time as women taking physical care of these children. At work, on the other hand, men spent fifty-two minutes a day longer on the job than women did. These discrepancies partly explain why workplaces look the way they do. A man who’s able to commit more time to the office or laboratory is naturally more likely to do better in his career than a woman who can’t. When decisions are made over who should take maternity or paternity leave, it’s also almost always mothers who take time out. Small individual choices, multiplied over millions of households, can have an enormous impact on how society looks. The Institute for Women’s Policy Research in the United States estimates that in 2015 women working full time earned only seventy-nine cents for every dollar that a man earned. In the United Kingdom, the Equal Pay Act was passed in 1970. But today, according to the Office for National Statistics, a gender pay gap of more than 18 percent still exists, although it’s falling. In the scientific and technical activities sector this gap is as big as 24 percent. Housework and motherhood aren’t the only things affecting gender balance. There’s outright sexism, too. In a study published in 2012, psychologist Corinne Moss-Racusin and a team of researchers at Yale University explored the possibility of gender bias in recruitment by sending out fake job applications for a vacancy of laboratory manager. Every application was identical except that half were given a female name and half a male name. When they were asked to comment on these potential employees, scientists rated women significantly lower in competence and hireability. They were also less willing to mentor them and offered far lower starting salaries. The only difference, of course, was that these applicants appeared to be female. Interestingly, the authors wrote in their paper, which appeared in the journal Proceedings of the National Academy of Sciences, “The gender of the faculty participants did not affect responses, such that female and male faculty were equally likely to exhibit bias against the female student.” Gender bias is so steeped in the culture, their results implied, that women were themselves discriminating against other women. Another study, published in 2016 in the world’s largest scientific journal, PLOS ONE, looked at how male biology students rated their female counterparts. Cultural anthropologist Dan Grunspan, biologist Sarah Eddy, and their colleagues asked hundreds of undergraduates at the University of Washington what they thought about how well others in their class were performing. “Results reveal that males are more likely than females to be named by peers as being knowledgeable about the course content,” they wrote. This didn’t reflect reality. Male grades were overestimated—by men—by 0.57 points on a four-point grade scale. Female students didn’t show the same gender bias. The year before, PLOS ONE had been forced to apologize after one of its own peer reviewers suggested that two female evolutionary geneticists who had authored a paper should add one or two male coauthors. The paper itself was about gender differences among doctorates. “Perhaps it is not so surprising that on average male doctoral students coauthor one more paper than female doctoral students, just as, on average, male doctoral students can probably run a mile a bit faster than female doctoral students,” wrote the reviewer. Another problem in parts of the sciences, the extent of which is only now being laid bare, is sexual harassment. In 2015 virus researcher Michael Katze was banned from entering the laboratory he headed at the University of Washington following a string of serious complaints, which included the sexual harassment of at least two employees. BuzzFeed News (which Katze tried to sue to block the release of documents) ran a lengthy account of the subsequent investigation, revealing that he had hired one employee “on the implicit condition that she submit to his sexual demands.” His case wasn’t an exception. In 2016 California Institute of Technology suspended a professor of theoretical astrophysics, Christian Ott, for also sexually harassing students. The same year two female students at the University of California, Berkeley, filed a legal complaint against assistant professor Blake Wentworth, who they claimed had sexually harassed them repeatedly, including inappropriate touching. This was not long after a prominent astronomer at the same university, Geoff Marcy, was found guilty of sexually harassing women over many years. So here, in all the statistics on housework, pregnancy, child care, gender bias, and harassment, we have some explanations for why so few women are at the top in science and engineering. Rather than falling into Lawrence Summers’s tantalizing trap of assuming the world looks this way because it’s the natural order of things, take a step back. Imbalance in the sciences is at least partly because women face a web of pressures throughout their lives, which men often don’t face. As bleak as the picture is in some places and some fields, the statistics also reveal exceptions. In certain subjects, women tend to outnumber men both at the university level and in the workplace. There are usually more women than men studying the life sciences and psychology. And in some regions, women are much better represented in science overall, showing that culture is also at play. In Bolivia, women account for 63 percent of all scientific researchers. In central Asia they are almost half. In India, where my family originate from (my dad studied engineering there), women make up a third of all students in engineering courses. Iran, similarly, has high proportions of female scientists and engineers. Mathematician Maryam Mirzakhani, the only woman to have won the prestigious Fields medal, was born in Tehran. If women were less capable of doing science than men, we wouldn’t see these variations, proving again that the story is more complicated than it appears. And like all stories, it also helps to go back to the start. Since its very earliest days, science has treated women as the intellectual inferiors of men. You would see it if you were to travel back to when the major academies of science were first created in Europe, according to Londa Schiebinger, a professor of the history of science at Stanford University and author of The Mind Has No Sex? Women in the Origins of Modern Science. In the sixteenth and seventeenth centuries, these academies were founded as forums for scientists, who usually worked independently, to come together and share ideas. Later, they bestowed honors, including membership. These days they also offer governments advice on science policy. Yet these prestigious institutions, so crucial to the growth of modern science, excluded women as a matter of course. The Royal Society of London, officially founded in 1663 and one of the oldest scientific institutions still around today, failed to elect any women to full