Inferior: How Science Got Women Wrong—and the New Research That's Rewriting the Story

by Angela Saini

Evolution was an alternative to religious stories that painted woman as man’s spare rib. Christian models for female be...

Although not a scientist herself, through Darwin’s work Gamble realized just how devastating the scientific method could be. If humans were descended from lesser creatures, the same as all other life on earth, then it made no sense for women to be confined to the home or subservient to men.

judging from her writing, a source of great anger. She believed that Darwin, though correct in concluding that humans evolved like every other living thing on earth, was clearly wrong when it came to the role that women had played in human evolution.

Marshalling history, statistics, and science, this was Gamble’s piercing counterargument to Darwin and other evolutionary biologists. She angrily tweezed out their inconsistencies and double standards. The peacock might have had the bigger feathers, she argued, but the peahen still had to exercise her faculties in choosing the best mate. And on the one hand, Darwin suggested that gorillas were too big and strong to become higher social creatures like humans. Yet at the same time he used the fact that men are on average physically bigger than women as evidence of their superiority.

In evolutionary terms, drawing assumptions about women’s abilities from the way they happened to be treated by society at that moment was narrow-minded and dangerous. Women had been systematically suppressed over the course of human history by men and their power structures, Gamble argued. They weren’t naturally inferior. They just seemed that way because they hadn’t been allowed the chance to develop their talents.

Eliza Burt Gamble’s message, like that of other scientific suffragists, proved popular. Their provocative message was that women had been cheated out of the lives they deserved, that equality was in fact their biological right.

The battle would take until 1918 in Britain, although only for women over the age of thirty. And when Gamble died in Detroit in 1920, it was just a month after the United States ratified the Nineteenth Amendment, which prohibited citizens from being denied the right to vote because of their sex.

It’s hard to picture the directions in which science might have gone if in those important days when Charles Darwin developed his theories of evolution, society hadn’t been as sexist as it was. We can only imagine how different our understanding of women might be now if Gamble had been taken more seriously.

It’s perhaps appropriate that one of the next breakthroughs in the science of sex differences came courtesy of a castrated cock.

They were foreshadowed by a strange experiment in 1849, carried out by a German medical professor, Arnold Adolph Berthold. He had been studying castrated cockerels, commonly known as capons. It was known that by removing their testes, these birds were left with deliciously tender meat, which made them a popular delicacy at the time. Aside from their meat, live capons looked different from normal cocks. They were more docile. They could also be spotted by a characteristic red comb on top of their heads and unusually droopy red wattles.

He took the testes from normal cockerels and transplanted them into capons to see what happened. Remarkably, he found the capons started to look and sound like cocks again. The testes were surviving inside them, and growing.

In 1891 another unusual experiment, this time in France by university professor Charles-Édouard Brown-Séquard, finally began to get to the root of the mystery. He suspected that male testes might contain some unknown substance that influenced masculinity.

He proved his hypothesis the hard and fast way, by repeatedly injecting himself with a concoction made out of the blood, semen, and juices from the crushed testicles of guinea pigs and dogs.

Sex hormones play a crucial role in determining how male or female a person looks even before birth. In the womb, it’s interesting to note, all fetuses start out physically female.

About seven weeks after the egg has been fertilized, testosterone produced by the testes begins physically turning the male fetuses into boys. “Testosterone says: ‘Make me externally male.’” Meanwhile another hormone stops this freshly male fetus from growing a uterus, fallopian tubes, and other female parts. As we grow older, hormones again play a role in puberty and beyond.

Tons of animal ovaries and testes were harvested and thousands of liters of horse urine were collected as scientists desperately searched for chemicals that defined what it meant to be male or female. The director of Dutch pharmaceutical company Organon described it as “finding gold in the urine of pregnant mares.”

In the archives of London’s Wellcome Library, which keeps an enormous trove of historical medical documents, I find an advertising pamphlet from around 1929, produced by the Middlesex Laboratory of Glandular Research in London.

In the early days of endocrinology, assumptions about what it meant to be masculine or feminine came from the Victorians. With the discovery of hormones, scientists had a new way to explain the stereotypes.

the prominent British gynecologist William Blair-Bell, for instance, believed that a woman’s psychology depended on the “state of her internal secretions” keeping her in “her normal sphere of action.”

Yeesh.

Researchers thought that sex hormones were doing more than just affecting reproductive behavior. They were also responsible for making men manlier, by the standards of the time, and for making women womanlier, again by the standards of the time. Reasoning in this way, scientists assumed the sex hormones belonged uniquely to each sex.

An interesting experiment in 1921 hinted at the possibility that all the assumptions that scientists were making about sex hormones might be wrong. A Viennese gynecologist revealed that treating a female rabbit with an extract from an animal’s testes changed the size of her ovaries. Later, to their shock, scientists began to realize that significant levels of androgens were present in women and of estrogen in men.

In fact, a male horse’s testes turned out to be one of the richest sources of estrogen ever found.

For a while, some scientists thought that female sex hormones might be turning up in men because they had eaten them. This bizarre food hypothesis was ditched when it gradually became clear that male and female gonads can in fact produce both hormones themselves.

Suddenly a spectrum opened up on which men could be more feminine and women more masculine, instead of opposites. Writing in 1939 at the end of what he described as this “epoch of confusion,” Herbert Evans at the Institute of Experimental Biology at the University of California, Berkeley, admitted, “It would appear that maleness or femaleness can not be looked upon as implying the presence of one hormone and the absence of the other. . . . Though much has been learned it is only fair to state that these differences are still incompletely known.”

Researchers in other fields began to explore the boundaries of sexual and gender identity. Cultural anthropologist Margaret Mead, for example, started writing at about the same time about masculine and feminine personalities, and how culture rather than biology might be influencing which ones people had.

According to endocrinologist Richard Quinton, common assumptions about testosterone have already been shown to be way off the mark. Women with slightly higher than usual levels of testosterone, he says, “don’t actually feel or appear any less feminine.”

He took saliva samples from traders and found that when their testosterone levels were above average, their gains were also above average. Another study in 2015 by a large team of scientists across the United Kingdom, United States, and Spain revealed that testosterone wouldn’t have made the traders any more aggressive. It just made them slightly more optimistic.

Quinton similarly claims to have seen no link between testosterone and aggression among his own patients, despite the stereotype that it makes people more violent. “I’m not sure where it comes from,” he tells me. “Urban myth?”

Sex is something scientifically distinct for most people. It’s defined by a certain package of genes and hormones as well as more obvious physical features, including a person’s genitals and gonads (although a small proportion of people are biologically intersex). Gender, meanwhile, is a social identity, influenced not only by biology but also by external factors such as upbringing, culture, and the effect of stereotypes.

we remain in the early days of this research. The biggest questions are still unanswered. Does the balance of sex hormones have an effect beyond the sexual organs and deeper into our minds and behavior, leading to pronounced differences between women and men? And what does this tell us about how we evolved? Is the traditional stereotype of the breadwinning father and the stay-at-home mother really part of our biological makeup, as Darwin assumed, or is it an elaborate social construction that’s unique to humans? Studies into sex differences are as powerful as they are controversial.

India’s 2011 census had already revealed that there were more than seven million fewer girls than boys age six and under. The overall sex ratio was more skewed in favor of boys than it had been a decade ago. One reason for this worsening in the records was the growing availability of prenatal scans, which for the first time allowed parents to find out the sexes of their babies easily and early enough to have selective abortions.

Khurana never wanted to have one of these prenatal scans, she tells me. In the end, she wasn’t given the choice. During her pregnancy, she claims she was tricked into eating some cake that contained egg, to which she’s allergic. Her husband, a doctor, then took her to a hospital, where a gynecologist advised her to have a kidney scan under sedation. It was then, she believes, he deliberately found out the sex of her babies without her consent or knowledge.

Ewwww

A few years later she stumbled on an old hospital report revealing the sex of her fetuses. She read it as proof that her husband had indeed carried out an ultrasound scan on her while she was pregnant. And that discovery helped launch a legal case against both him and the clinic, which is still making its way through the notoriously slow Indian courts by the time I interview her, ten years since the birth of her daughters. Her husband and the clinic have both strongly denied her allegations in the press.

However well hidden the selective abortions, murders, and abuse of mothers and their girls, the countrywide statistics don’t lie. Reality is laid bare in the grotesquely uneven sex ratios. The United Nations report The World’s Women 2015 says, “For those countries in which the sex ratio falls close to or below the parity line, it can be assumed that discrimination against girls exists.”

A similar gender imbalance was uncovered in a 2002 study in Nepal, northeast of India, by public health researchers Miki Yamanaka and Ann Ashworth, also from the London School of Hygiene and Tropical Medicine. They looked at how much work children are expected to do to support their families and found that girls worked twice as long as boys and that their work was also more physically demanding.

What makes the mortality figures even more shocking is that, contrary to assumptions about women being the weaker sex, a baby girl is statistically more robust than a baby boy. She’s naturally better built to live.

The first month following birth is the window in which humans are at their greatest risk of death. A million babies die on the day of their birth every year. But if they receive exactly the same level of care, females are statistically less likely to die than males.

And having researched the issue in such depth, Lawn concludes that boys are at around a 10 percent greater risk than girls in that first month—and this is at least partly, if not wholly, for biological reasons.

Elsewhere, child mortality statistics bear this out. For every thousand live births in sub-Saharan Africa, ninety-eight boys compared with eighty-six girls die by the age of five.

Research published by scientists at the University of Adelaide in the journal Molecular Human Reproduction in 2014 showed that newborn girls may be healthier on average because a mother’s placenta behaves differently depending on the sex of the baby.

“Pretty much at every age, women seem to survive better than men,” confirms Steven Austad, international expert on aging and chair of the biology department at the University of Alabama, Birmingham. He describes women as being more “robust.”

Digging through the Human Mortality Database, a collection of longevity records from around the world and founded by German and American researchers in 2000, he was surprised to discover that the phenomenon really does transcend time and place. The database now covers thirty-eight countries and areas. But his favorite example is Sweden, which has kept some of the most thorough and reliable demographic data anywhere. In 1800 life expectancy at birth in Sweden stood at thirty-three years for women and thirty-one for men. In 2015 it was about eighty-three years for women and about seventy-nine for men.

The picture of this survival advantage is starkest at the end of life. The Gerontology Research Group keeps a list online of all the people in the world who they have confirmed are living past the age of 110. I last checked the site in July 2016. Of all these “supercentenarians” in their catalogue, just two were men. Forty-six were women.

For more than a century, scientists have painstakingly studied our anatomy, even collected thousands of liters of horse urine to root out the chemicals that make men more masculine and women more feminine. Their search for sex differences has shown no boundaries. But when it comes to why women might be more physically robust than men—why they are better survivors—research has been scarce. Even now, only scraps of work here and there point to answers.

One of his papers shows that in the United States in 2010, women died at lower rates than men from twelve of the fifteen most common causes of death, including cancer and heart disease, when adjusted for age. Of the three exceptions, their likelihood of dying from Parkinson’s or stroke was about the same. And they were more likely than men to die of Alzheimer’s disease.

One explanation for this gap is that higher levels of estrogen and progesterone in women might be protecting them in some way. These hormones don’t just make the immune system stronger but also more flexible, according to Sabine Oertelt-Prigione, a researcher at the Institute of Gender in Medicine at the Charité university hospital in Berlin.

The hormonal changes that affect a woman’s immune system during pregnancy also take place on a smaller scale during her menstrual cycle, and for the same reasons. “Women have more plastic immune systems. They adapt in different ways,” says Oertelt-Prigione.

Researchers know that a certain type of T cell that’s crucial to managing the body’s response to infections becomes more active in the second half of a woman’s menstrual cycle, when she’s able to get pregnant.

The discovery that sex hormones and immunity might be linked is fairly recent. In men, scientists have explored connections between testosterone and lower immunity, although the evidence is relatively thin. In 2014 Stanford University researchers found that males with the highest levels of testosterone, for example, had the lowest antibody response to a flu vaccine, which meant they were the least likely to be protected by the jab.

In women, the connection is far clearer; so much so that patients themselves have noticed these fluctuations. For years, doctors assumed that a woman’s immunity couldn’t be changing during her menstrual cycle. If she did report a difference in pain levels, doctors might dismiss it as premenstrual syndrome or some vague psychological complaint. It was only when these links were increasingl...