Certainly, there is far more acknowledgement now of the role of experience and environment compared with a century or so ago. In the early twentieth century, ‘[g]enius was considered an innate quality which would naturally be manifested if it were possessed’, as psychologist Stephanie Shields summarises.5 No one now, I should think, would agree with this. And yet there remains, in some quarters, a Victorian-style attachment to notions of innate, immutable, inevitable qualities. How else to explain why the Greater Male Variability hypothesis – the idea that men are more likely to be outliers, good or bad (‘more prodigies, more idiots’6) – appears to be no less appealing now than it was over a century ago?7 In the early twentieth century, the Greater Male Variability hypothesis offered a neat explanation of why men so outnumbered women in eminence, despite the fact that there was little sex difference in the average scores of men and women on psychological tests. As Edward Thorndike (the sociologically unimaginative psychologist we met in the Introduction) explained it in 1910:
In particular, if men differ in intelligence and energy by wider extremes than do women, eminence in and leadership of the world’s affairs of whatever sort will inevitably belong oftener to men. They will oftener deserve it.8
And today, it seems, they oftener deserve high-ranking positions in mathematics and science, according to Lawrence Summers:
It does appear that on many, many different human attributes – height, weight, propensity for criminality, overall IQ, mathematical ability, scientific ability … there is a difference in the standard deviation and variability [statistical measures of the spread of a population] of a male and a female population. And that is true with respect to attributes that are and are not plausibly, culturally determined. If one supposes, as I think is reasonable, that if one is talking about physicists at a top twenty-five research university … small differences in the standard deviation will translate into very large differences in the available pool …9
I’d love to know, by the way, how extreme noncriminality manifests itself. (Number of Supreme Court judges, perhaps?) But more to the point, the assertion that males are more variable in all regards – whether you’re talking weight, height or SAT scores – certainly helps to frame variability as ‘a guy thing’ across the board. The implication is that there is something inevitable and immutable about greater male variability in mathematical and scientific ability. Certainly, in the furor that followed, Steven Pinker defended the idea of the timeless, universal nature of greater male variability (‘biologists since Darwin have noted that for many traits and many species, males are the more variable gender’).10 Susan Pinker also plays the argument that ‘[m]en are simply more variable’ in the shadow of the Summers controversy.11 Her book displays a graph showing the findings from a report published by psychologist Ian Deary and his colleagues – a massive IQ study of 80,000 Scottish children born in 1921. Boys’ and girls’ average IQs were the same, the study found, but the boys’ scores were more variable. But as the educational psychologist Leta Stetter Hollingworth pointed out in 1914, and as Ian Deary and his colleagues felt compelled to reiterate nearly 100 years later, ‘the existence of sex differences either in means or variances in ability says nothing about the source or inevitability of such differences or their potential basis in immutable biology.’12 This should be more obvious to us now than it was a hundred years ago when capacity for eminence was regarded as something that was simply ‘in there’. We realise that, as Grossi has pointed out, ‘[m]athematics and science are learned in a period of time that spans across several years; passion and application need to be constantly nurtured and encouraged.’13
And, as it turns out, contemporary investigations of variability – both in the general population and in the most intellectually blessed pockets – have been showing that ‘inevitable’ and ‘immutable’ are adjectives that need not apply when it comes to describing greater male variability in mental ability. One cross-cultural study, published several years before the Summers debacle, compared sex differences in variability in verbal, maths and spatial abilities to see if the greater male variability in the United States was invariably seen in other countries. It was not. In each cognitive domain, there were countries in which females’ scores were more variable than males’.14
More recently, several very large-scale studies have collected data that offer tests of the Greater Male Variability hypothesis by investigating whether males are inevitably more variable in maths performance, and always outnumber females at the high end of ability. The answer, in children at least, is no. In a Science study of over 7 million United States schoolchildren, Janet Hyde and her team found that across grade levels and states, boys were modestly more variable than girls. Yet when they looked at the data from Minnesota state assessments of eleventh graders to see how many boys and girls scored above the 95th and 99th percentile (that is, scored better than 95 percent, or 99 percent, of their peers) an interesting pattern emerged. Among white children there were, respectively, about one-and-a-half and two boys for every girl. But among Asian American kids, the pattern was different. At the 95th percentile boys’ advantage was less, and at the 99th percentile there were more girls than boys.15 Start to look in other countries and you find further evidence that sex differences in variability are, well, variable. Luigi Guiso’s cross-cultural Science study also found that, like the gender gap in mean scores, the ratio of males to females at the high end of performance is something that changes from country to country. While in the majority of the forty countries studied there were indeed more boys than girls at the 95th and 99th percentiles, in four countries the ratios were equal or even reversed. (These were Indonesia, the UK, Iceland and Thailand.)16 Two other large cross-cultural studies of maths scores in teenagers have also found that although males are usually more variable, and outnumber girls at the top 5 percent of ability, this is not inevitably so: in some countries females are equally or more variable, or are as likely as boys to make it into the 95th percentile.17
Of course, scoring better than 95 or 99 percent of your school peers in mathematical ability is probably a baseline condition for eventually becoming a tenured Harvard professor of mathematics: like having hands, if you want to be a hairdresser. Top scorers on standardised maths tests may be what one group of researchers, rather stingily, refers to as ‘the merely gifted’.18 But also changeable is the proportion of girls identified in what’s called the Study of Mathematically Precocious Youth (SMPY), which gives the quantitative section of the Scholastic Aptitude Test (the SAT) to kids who, theoretically, are way too young to take it. Children who score at least 700 (on a 200 to 800 scale) are defined as ‘highly gifted’. In the early 1980s, highly gifted boys identified by the SMPY outnumbered girls 13 to 1. By 2005, this ratio had plummeted to 2.8 to 1.19 That’s a big change.
Being highly gifted is, I imagine, rather nice, but at the risk of swelling the head of any research mathematicians in top-ranked institutions who happen to be reading this book, they need to have made it onto the next rung of the giftedness ladder, and be ‘profoundly gifted’. And here again – in this literally one-in-a-million category – there can be striking differences in female representation, depending on time, place and cultural background. The International Mathematical Olympiad (IMO) is a nine-hour exam, taken by six-person teams sent from up to ninety-five countries. The length of the exam is off-putting enough, but the six problems within it are also so difficult that every year just a few students (or sometimes even none) get a perfect score. We tend not to hear that much about maths competitions (perhaps in part because, let’s be honest, live televised coverage of a nine-hour maths exam would not make for compelling viewing). So it’s probably worth pointing out that these competitions are not female-free zones. Girls are among those who achieve perfect scores. Girls, like US team member Sherry Gong, win medals for outstanding performance. Gong won a silver medal in the 2005 IMO and a gold medal in 2007. The girl can do maths – and she’s not alone. As the researchers po
int out, ‘numerous girls exist who possess truly profound ability in mathematical problem solving.’20
But an equally important insight from their analysis is what a difference where you come from makes for your chances of being identified and nurtured as a maths whiz. Between 1998 and 2008 no girls competed for Japan. But next door, seven girls competed for South Korea (which, by the way, ranks higher than Japan). A profoundly gifted young female mathematician in Slovakia has a five times greater chance of being included on the IMO team than her counterpart in the neighbouring Czech Republic. (Again, Slovakia outperforms the Czech Republic. I say this not to be competitive, but merely to show that teams with more girls have not been scraping the bottom of the barrel.) The ratio of female members on IMO teams among the top 34 participating countries ranges from none at all, to 1 in 4 (in Serbia and Montenegro). This is not random fluctuation, but evidence of ‘socio-cultural, educational, or other environmental factors’ at work.21
In fact, we can see this very clearly even within North America. Being underrepresented on the IMO team, or the Mathematical Olympiad Summer Program (MOSP), is not, as you might assume, a girl problem. It’s more subtle and interesting than that. First of all, if you’re Hispanic, African American or Native American, it matters not whether you have two X chromosomes or one – you might as well give up now on any dreams of sweating for nine hours over some proofs. Then within girls, interesting patterns emerge. Asian American girls are not underrepresented, relative to their numbers in the population. But that doesn’t mean that it’s even simply a white girl problem. Non-Hispanic white girls born in North America are sorely underrepresented: there are about twenty times fewer of them on IMO teams than you’d expect based on their numbers in the population, and they virtually never attend the highly selective MOSP. But this isn’t the case for non-Hispanic white girls who were born in Europe, immigrants from countries like Romania, Russia and the Ukraine, who manage on the whole to keep their end up when it comes to participating in these prestigious competitions and programmes. The success of this group of women continues into their careers. These women are a hundred times more likely to make it into the maths faculty of Harvard, MIT, Princeton, Stanford or University of California–Berkeley than their native-born white counterparts. They do every bit as well as white males, relative to their numbers in the population. As the researchers conclude:
Taken together, these data indicate that the scarcity of USA and Canadian girl IMO participants is probably due, in significant part, to socio-cultural and other environmental factors, not race or gender per se. These factors likely inhibit native-born white and historically underrepresented minority girls with exceptional mathematical talent from being identified and nurtured to excel in mathematics. Assuming environmental factors inhibit most mathematically gifted girls being raised in most cultures in most countries at most times from pursuing mathematics to the best of their ability, we estimate the lower bound on the percentage of children with IMO medal-level mathematical talent who are girls to be in the 12%–24% range [i.e., the levels seen in countries like Serbia and Montenegro]…. In a gender-neutral society, the real percentage could be significantly higher; however, we currently lack ways to measure it.22
That’s a lot of squandered talent, and among boys, too. As the researchers acknowledge, the data they collected can’t answer the question of whether females – in a perfectly gender-equal environment – could match (or, why not be bold, perhaps even surpass) males in maths. But the gender gap is narrowing all the time, and shows that mathematical eminence is not fixed, or hardwired or intrinsic, but is instead responsive to cultural factors that affect the extent to which mathematical talent is identified and nurtured, or passed over, stifled or suppressed in males and females.
And so this is all good news for Lawrence Summers, who said that he ‘would far prefer to believe something else’ than the ‘unfortunate truth’ that, in part, ‘differing variances’ lie behind women’s underrepresentation in science.23 And for Pinker, too, who warned Summers’ detractors that ‘[h]istory tells us that how much we want to believe a proposition is not a reliable guide as to whether it is true.’24 Evidence for the malleability of the gender gap in ability and achievement is there. And this is important because, as we learned in the first part of the book, it makes a difference what we believe about difference. Stanford University’s psychologist Carol Dweck and her colleagues have discovered that what you believe about intellectual ability – whether you think it’s a fixed gift, or an earned quality that can be developed – makes a difference to your behaviour, persistence and performance. Students who see ability as fixed – a gift – are more vulnerable to setbacks and difficulties. And stereotypes, as Dweck rightly points out, ‘are stories about gifts – about who has them and who doesn’t.’25 Dweck and her colleagues have shown that when students are encouraged to see maths ability as something that grows with effort – pointing out, for example, that the brain forges new connections and develops better ability every time they practise a task – grades improve and gender gaps diminish (relative to groups given control interventions).26 The Greater Male Variability hypothesis, of course, endorses the view that very great intellectual ability is indeed a fixed trait, a gift bestowed almost exclusively on men. Add a little talk of women’s insufficient white matter volumes, or their plump corpora callosa, and the ingredients for a self-fulfilling prophecy are all in place.
The sensitivity of the mind to neuroscientific claims about difference raises ethical concerns.27 A recent study by University of Exeter psychologist Thomas Morton and his colleagues asked one group of participants to read the kind of passage that is the bread-and-butter of a certain type of popular gender science book. It presented essentialist theories – that gender difference in thinking and behaviour are biological, stable and immutable – as scientifically established facts. A second group read a similar article, but one in which the claims were presented as being under debate in the scientific community. The ‘fact’ article led people to more strongly endorse biological theories of gender difference, to be more confident that society treats women fairly and to feel less certain that the gender status quo is likely to change. It also left men rather more cavalier about discriminatory practices: compared with men who read the ‘debate’ article, they agreed more with statements like, ‘If I would work in a company where my manager preferred hiring men to women, I would privately support him’, and ‘If I were a manager in a company myself, I would believe that more often than not, promoting men is a better investment in the future of the company than promoting women.’ They also felt better about themselves – a small consolation indeed to women, I think you’ll agree.
Interestingly, for men who tend to the view that sex discrimination is a thing of the past, the appeal of essentialist research is enhanced by evidence that the gender gap is closing, Morton and his colleagues also found. Participants were asked to rate research that investigated the genetic basis of sex differences in mouse brains, as well as claiming that similar factors may underlie psychological gender differences in humans. Beforehand they read an article, supposedly from a national newspaper, arguing either that gender inequality was stable, or closing. After reading about women’s gains these men more readily agreed that ‘this type of research should continue, deserved more funding, was good for society, represented the facts about gender differences, and made a major contribution to understanding human nature’.28
Taken together, Morton’s findings suggest that women’s gains will, in certain quarters, increase demand for essentialist research. As this research trickles back into society, people will turn away from social and structural explanations of gender difference. They will give up on the idea of further social change. And, to help the belief in the inevitability of inequality come true, workplace discrimination against women will increase.
It is, I think, time to raise the bar when it comes to the interpretation and communication of sex differences in the brain. How
long, exactly, do we need to learn from the mistakes of the past?
As we’ve seen in this part of the book, speculating about sex differences from the frontiers of science is not a job for the faint-hearted who hate to get it wrong. So far, the items on that list of brain differences that are thought to explain the gender status quo have always, in the end, been crossed off.29 But before this happens, speculation becomes elevated to the status of fact, especially in the hands of some popular writers. Once in the public domain these supposed facts about male and female brains become part of the culture, often lingering on well past their best-by dates. Here, they reinforce and legitimate the gender stereotypes that interact with our minds, helping to create the very gender inequalities that the neuroscientific claims seek to explain.30
‘It’s made me think a lot more about genetic influence, she’s got two X chromosomes, and that somehow, I don’t know, because we don’t push the Barbie stuff at all, in fact I would prefer her not to have it … so I’m kind of intrigued at how even though I am sort of doing the middle of the road, that she is nonetheless veering over towards being more feminine, and I think it’s genetic.’ (White, upper-middle class, lesbian mother, describing her three-year-old daughter).
—Comment from Emily Kane’s interview study (2006)
When I tell parents that I’m writing a book about gender, the most common response I get is an anecdote about how they tried gender-neutral parenting, and it simply didn’t work. (The next most frequent reaction is a polite edging away.) This is a common experience, found sociologist Emily Kane. She interviewed forty-two parents of preschoolers, from a wide range of backgrounds, and asked them why they thought that their sons or daughters sometimes behaved in sex-typed ways. Many parents called on evolutionary or divine reasons to explain why there should be innate biological differences between girls and boys (although most also mentioned social factors). But over a third of the interviewed parents – mostly white and middle or upper middle class – expressed the ‘biology as fallback’ position, as Kane called it. Only by process of elimination did they come to the conclusion that differences between boys and girls were biological. Believing that they practised gender-neutral parenting, biology was the only remaining explanation:
Delusions of Gender Page 21