Inferior: The True Power of Women and the Science that Shows It

by Angela Saini

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 raises is, how much of an effect do hormones have on how we think and 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. The second thing is sexual orientation. Most women are interested in men, and most men aren’t.’ The third is childhood play behaviour. Studying girls with congenital adrenal hyperplasia, who have higher than normal levels of testosterone, she found, ‘Rough-and-tumble play is increased in girls exposed to androgens.

She and others found in study after study that boys on average really do prefer to play with trucks and cars, while girls on average prefer dolls. ‘The main toys are vehicles and dolls. Those are the most gendered type of toys,’ she says. A study that Hines and her colleagues carried out on infants in 2010, observing how long they looked at one toy rather than another, suggested that these preferences start to emerge before the age of two.

This difference in toy choices, however, is quite a leap from the theory that the brains of men and women are deeply, structurally different because of how much testosterone they’ve been exposed to. It’s also a considerable distance from Simon Baron-Cohen’s claim that there’s such a thing as a typical male brain and a typical female brain – one that likes mathematics, and another that prefers coffee mornings. For Baron-Cohen to be right, there would have to be noticeable gaps in lots of other behaviours as well.

‘sex difference in empathising and systemising is about half a standard deviation’. This would be equivalent to a gap of about an inch between the average heights of men and women. It’s small. ‘That’s typical,’ she says. ‘Most sex differences are in that range. And for a lot of things, we don’t show any sex differences.’

They concluded that the psychological gaps between women and men were far smaller than the gender differences that existed among women and among men in society. In 2010 Hines repeated this exercise, using more recent research. She found that only the tiniest gaps, if any, existed between boys’ and girls’ fine motor skills, ability to perform mental rotations, spatial visualisation, mathematical ability, verbal fluency and vocabulary.

Beyond gender identity and toy preference, on pretty much every other behavioural and cognitive measure that scientists have investigated (in a field that has left few stones unturned in its quest for evidence), girls and boys overlap hugely. Indeed, almost entirely. A study by Hines exploring colour preferences, for example, found that infant girls had no more of a love of pink than boys did.

‘Even though on the average there is no sex difference in IQ, I think still boys get encouraged at the top. I think in some social environments they don’t get encouraged at all, but I think in affluent, educated social environments, there is still a tendency to expect more from boys, to invest more in boys,’

it’s only at the extremes where researchers seem to find any discrepancies. ‘It’s all a bell curve … and for the kids in the middle there’s almost no sex difference there at all,’ she says.

‘gender differences fall on a continuum, not into two separate buckets’. ‘I think that people tend to think of this in an either–or kind of way,’ agrees Teodora Gliga. Either girls and boys are born very different, or they’re the same. The scientific picture emerging now is that there may be very small biological differences, but that these can get so easily reinforced by society that they appear much bigger as a child grows. ‘My opinion is that you will find differences wherever they were reinforced, because we love categories … we need to have categories. And so once we’ve decided, once we’ve labelled “This is a girl,” “This is a boy,” then we have so many culturally strong biases that we maybe produce differences in abilities.

In 1888 she gave a talk titled ‘Sex in Brain’ at the convention of the International Council of Women in Washington, DC, in which she argued against some scientists’ claim that because women’s brains were lighter than men’s, by extension, women must also be less intelligent. One of the most high-profile men to suggest this was William Alexander Hammond, no less than a former Surgeon General of the US Army and one of the founders of the American Neurological Association.

In the 1970s sex-difference research had experienced a decline, because gender scholars and women’s rights campaigners argued that it was sexist to look for biological gaps between women and men, just as it was racist to look for differences between black and white people. Gradually, though, it became acceptable again.

An earlier behavioural study they carried out on the same group of people, published in 2012, claimed to see ‘pronounced sex differences, with the females outperforming males on attention, word and face memory, and social cognition tests, and males performing better on spatial processing and motor and sensorimotor speed’. They argued that their new wiring diagrams, produced using the power of diffusion tensor imaging, could explain some of these differences.

I was horrified,’ says Rippon. Studies, including some carried out by Ruben Gur at the University of Pennsylvania, saw sex differences in the brain when it came to almost everything. Examples included verbal and spatial tasks, listening to someone read, responding to psychological stress, experiencing emotion, eating chocolate, looking at erotic photos, and even smelling. One claimed that the brains of homosexual men had more in common with the brains of straight women than with those of straight men. ‘I just got drawn into it because I thought this is horrendous, that it is being used in exactly the same way as people in the past saying women shouldn’t go to university because it will mess up their reproductive systems,’ she tells me.

when Bennett was looking for evidence of false positives in brain imaging, he dug out this old scan of the salmon. Proving the critics right and showing how even the best technologies can mislead, it showed three small red areas of activity close together in the middle of the fish’s brain. The dead fish’s brain.

The vast majority of experiments and studies show no sex difference, she says. But they’re not the ones that get published. ‘I describe this as an iceberg. You get the bit above the water, which is the smallest but most visible part, because it’s easy to get studies published in this area. But then there’s this huge amount under the water where people haven’t found any differences.’

In her 2010 book Delusions of Gender, the psychologist Cordelia Fine coins the term ‘neurosexism’ to describe scientific studies that fall back on gender stereotypes, even when these stereotypes are themselves unproven. Ruben Gur’s 2014 study on sex differences in white matter between men and women, Gina Rippon tells me, is among those that deserve to be described as ‘extremely neurosexist’.

‘If you look at it as a scaling problem, the grey and white matter will change as a function of the brain size, so even that is to do with size.’

‘Sex differences in the brain are irresistible to those looking to explain stereotypic differences between men and women,’ she told reporters when her paper came out. ‘They often make a big splash, in spite of being based on small samples. But as we explore multiple datasets and are able to coalesce very large samples of males and females, we find these differences often disappear or are trivial.’

‘Science doesn’t operate in a political vacuum,’ she says. ‘I think there are some sciences which can be more objective than others. But we are dealing with people, we’re not the Large Hadron Collider.’ Unlike particle physics, neuroscience is about humans, and it has profound repercussions for how people see themselves.

we like to justify the social system we’re in. If everyone around us thinks that women are less rational or worse at parking than men, even the thinnest piece of information that reinforces that assumption will be pasted into our minds. Research that confirms what appears to be obvious seems right. Anything that contradicts it, meanwhile, is dismissed as aberrant.

Neuroscientist Eleanor Maguire at University College London discovered that the mental feat of memorising the layout of twenty-five thousand streets and thousands of landmarks, known as ‘The Knowledge’, could be changing the size of a cabbie’s hippocampus, a region associated with memory.

Studying musicians, basketball players, ballet dancers, jugglers and mathematicians has confirmed that brain plasticity is real. In the context of sex difference research, it also raises an important question: if intense experience and learning a new task can shape a person’s brain, could the experience of being a woman shape it as well? Could plasticity therefore explain the sex differences that are sometimes seen in the adult brain?

Rippon, Fine, Jordan-Young and Kaiser have argued that biology and society are ‘entangled’ – that they work in concert with each other, through mechanisms like plasticity, to create the complicated picture we call gender.

‘Challenging the notion of universal male advantage in mathematics, sex differences in average mathematics test performance are not found in many nations and are even reversed (female advantage) in a few,’ Miller and Halpern observe. What looks like a biological difference in one particular place and time, can turn out to be a cultural difference after all.

‘We’re good at what the brain allows us to be good at, and as we become good at something, our brain changes to enable that,’ explains Paul Matthews. Playing action video games or with construction sets, for instance, improves spatial skills. So if a young boy happens to be given a building set rather than a doll to play with, the stereotype of males having better spatial skills is physically borne out. Society actually ends up producing a biological change.

Plasticity and entanglement imply that every single brain must be unique, for the simple reason that every person’s life experience is different. It is this, argues Daphna Joel, that makes looking for differences between groups so fraught with error. Evidence of sex difference in the brain is statistically problematic because each brain varies from the next.

Joel’s research reveals that, depending on the study, between 23 and 53 per cent of people show variability in their brains, with features that are associated with both men and women. Meanwhile, the proportion of people in the studies she has analysed who have purely masculine or purely feminine brain features is between none and 8 per cent.

there can’t be any such thing as an average male or an average female brain. We are all, each one of us, a mix. Our brains are intersex.

Writing our evolutionary story isn’t easy, and it’s also plagued by controversy. As Charles Darwin’s work in the nineteenth century shows, 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 inferior sex. It’s taken more than a century for researchers to overturn these old ideas and rewrite this flawed tale.

If we are natural cooperative breeders – a species in which alloparents are part of the fabric of families – it’s unreasonable to expect women to manage without any help. For Hrdy, a feminist, this line of research has obvious political implications. It reinforces why lawmakers shouldn’t outlaw abortion and force women to have babies they feel they cannot raise or do not want. It also highlights how important it is that governments provide better welfare and childcare for mothers,

‘We see a huge range of plasticity in how much engagement there is in human males,’ says Richard Bribiescas. ‘So you can be the most doting and caring father, and everything is great and lovely, to a father that’s sort of engaged and maybe just brings food and resources home, to the ultimate, very horrific cases of things like infanticide.’ If society expects men to be involved in childcare, they are, and they can do it well. If society expects them to be hands-off, they can do that too. This plasticity is unique to humans. ‘In other great apes and other primates you simply don’t see that. They’re locked into one strategy,’

If, in our evolutionary history, caring for children is something that would have been done not just by mothers, but also by fathers, siblings, grandmothers and others, the traditional portrait we have of family life starts to crack.

This all points to the possibility that living arrangements among early humans could have taken any number of permutations. Monogamy may not have been the rule. Women, if they weren’t tied to their children all the time, would have been free to go out to get food, and perhaps even to hunt. The Victorian ideal that Charles Darwin based his understanding of women upon – mother at home, taking care of the children, hungrily waiting for father to bring home the bacon – is left out in the cold.

Given this bias, she said, it wasn’t surprising that anthropologists had failed to ask just what it was that females were doing while the males were out hunting. ‘A theory that leaves out half of the human species is unbalanced,’

The title of Linton’s passionate talk, ‘Woman the Gatherer’, was seen as the female counterpoint to ‘Man the Hunter’. And it became a rallying cry for other researchers who were determined to bring women to the heart of the human evolutionary story.

What digging sticks, slings and food bags all have in common is that they’re either wooden or made of skin or fibre, which means they break down and disappear over time. They leave no trace in the fossil record, unlike hard-wearing stone tools that archaeologists have assumed were used for hunting. This is one reason, says Zihlman, that women’s inventions, and consequently women themselves, have been neglected by evolutionary researchers.

Were anthropologists right in thinking that male hunters drove forward the development of human communication and brain size? Sarah Hrdy’s work on primate infants and mothers supports Sally Linton’s suggestion that language probably evolved not through hunting, but more likely through the complex and subtle interactions between babies and their carers.

Seen from an evolutionary context, strength like this makes sense. Our sedentary lifestyles, and female beauty ideals that prize skinniness and fragility over size and strength, can blind us to what women’s bodies are capable of. But if the lives of modern-day hunter-gatherers are anything to go by, our female ancestors would have done plenty of hard physical work.

‘The thing about hunter-gatherer societies is that there is less rigid division of human labour because everybody learns everything,’ explains Zihlman. In our ancient past, thousands of years ago, it’s quite possible that men would have been far more involved in childcare and gathering, while women would have been hunters.

The Nanadukan Agta then subsisted by fishing and by hunting for wild game such as pigs and deer, using bows and arrows and the help of dogs. What made them unusual was that Agta women hunted and fished.

There’s no biological commandment that says women are natural homemakers and unnatural hunters, or that hands-on fathers are breaking some eternal code of the sexes.

We sometimes imagine sexual equality to be a modern invention, a product of our enlightened, liberal societies. But anthropologists have long known that in many societies men and women have existed on equal terms.

Rebecca Bliege Bird, who has studied women hunter-gatherers in Australia, agrees. ‘There’s no reason why women wouldn’t hunt where hunting is an economically productive and predictable thing to do.’ One example she gives me is that of the Meriam, an indigenous Australian society living in the Torres Strait Islands.

When it comes to family and working life, the biological rule seems to be that there were never any rules. While the realities of childbirth and lactation are fixed, culture and environment can dictate how women live just as much as their bodies do.

You’re at university, and a stranger of the opposite sex sidles up to you. ‘I’ve been noticing you around campus. I find you to be very attractive,’ they say. Before you know it, the mysterious person is inviting you back to their room to sleep with them. It may be the least creative way of picking someone up, but if it works on you, then research suggests you’re almost certainly a man.

The results were stark. Even though men and women were equally likely to agree to go on a date with a stranger, none of the women would sleep with one. Three-quarters of the men, on the other hand, were willing to have sex with a woman they didn’t know.

It comes down to the fact, some biologists say, that males and females want fundamentally different things. They’re stuck in an endless evolutionary tussle – males indiscriminately chasing any female so as to boost their chances of fathering the most children; and females trying to escape unwanted male attention in the careful search for the best-quality father for their offspring.

Darwin had reasoned that when one sex has to compete for mates, there’s greater pressure on it to evolve the features the other sex is looking for. It needs to be strong enough to beat off the competition, too. He called this evolutionary process ‘sexual selection’. And his observations suggested that males faced far more of this pressure than females. This would explain why the males of certain species, including our own, tend to be bigger and stronger than the females. It explains, too, such marvels of nature as the lion’s mane and the peacock’s flamboyant blue and green plumage.

Trivers realised that females must be choosier and less promiscuous in selecting a mate than males because they have a lot more to lose from making a bad choice. Take the example of humans: men produce lots of sperm, and don’t necessarily need to invest in their children, while women have only a couple of eggs to fertilise at a time, followed by nine months of pregnancy and many years of breastfeeding and child-raising.