Thomas Jackson, American Renaissance, November 1994

Eve’s Rib: The Biological Roots of Sex Differences, Robert Pool, Crown Publishers, 1994, 308 pp.

Perhaps the defining characteristic of the liberal is his ability to believe so many things that are obviously untrue. In fact, a list of the most common social beliefs for which there is no evidence is a good summary of liberalism: instruction raises intelligence, genetics does not apply to people, all races are equal, poverty causes crime, multi-racialism is good, welfare mothers want to work, all cultures are equal, men and women are essentially the same.

Of all these silly ideas, the silliest may be that men and women behave differently only because a “sexist” society teaches them to. Even a few liberals have given up thinking this.

Robert Pool’s Eve’s Rib is a book about recent research on sex differences, written for people who would rather believe that men and women are the same. Mr. Pool himself would rather believe that, too, and the book is full of apologies and reassurances that throw an edifying light on how painful it is for liberals to give up their illusions. Despite its hand-holding tone, though, the book covers a lot of ground and leaves no doubt that men and women behave differently because they are inherently different.

Physical Capabilities

Besides the obvious bodily differences that not even the wildest liberals and feminists can deny, the physical capabilities of men and women differ in many interesting ways. Women’s eyes adjust to the dark more quickly than men’s and women are better at picking out a faint patch of light in a dim room. Women can detect odors too faint for men to smell, and they are better at telling odors apart. Women have better precise control over their arms and hands, which gives them an advantage in playing musical instruments or doing fine embroidery.

Men and women have different tolerance levels for noise. If they are told to turn up the volume of a tone to the point where it is just a little too loud to be comfortable, the average man will turn it up eight decibels higher — or twice as loud — as the average woman.

Women are consistently better than men at certain kinds of memory tests. They are likely to recall more details of a story that was read to them, and to remember the furnishings of a room or the different objects in a cluttered photograph.

One of the most solidly confirmed sexual differences is in the ability to understand spatial relations. The Vandenberg mental rotations test assesses a person’s ability to imagine what a three-dimensional shape would look like if it were turned one way or another. Five out of six men outperform the average woman.

This male advantage has practical consequences. Men can read maps better than women and are better mechanics, architects, and engineers. Women can shoot at stationary targets as well as men, but have a much harder time hitting a moving target. Women have won national rifle competitions but they are poor skeet shooters.

Spatial ability seems to be related to the ability to do mathematics. Mathematicians are almost invariably men, and this is not because women are kept out of the field. Every year, there is a nation-wide search to find the most mathematically gifted youngsters and give them special training. Some of the participants are girls, who love math, are the best math students in their schools, and are encouraged by parents and teachers. However, they are never as good as the most gifted boys.

As math geniuses get older, they show another typical sex difference. Men tend to be obsessively devoted to math, while women have broader interests and often go into other fields.

Females have a well-established superiority in language. They speak in longer sentences at earlier ages than boys, and make fewer grammatical errors. In elementary and junior high school, they are likely to get better grades. If told to make a list of words beginning with a certain letter, the average woman makes a longer list than the average man — not because she has a larger vocabulary but because she is better at recalling words. Women are also better at unscrambling anagrams.

As Mr. Pool explains, these differences are not spread evenly across the sexes. The male advantage in math is most pronounced at the highest levels of ability, with little difference to be found between groups of male and female mediocrities. The female verbal advantage, on the other hand, is mostly at the low end. Men are three times more likely than women to stutter or be dyslexic. However, the most verbally gifted men are the equals of the most gifted women. For example, the average boy spells worse than 70 percent of girls, but the winner of a spelling bee is just as likely to be a boy as a girl.

Researchers have tested every possible environmental influence they could think of that would explain differences of this kind, but none withstands scrutiny. Men and women are different and, as we shall see, Mr. Pool makes an air-tight case for the view that it is hormones — not “sexism” — that makes them different.

People v. Objects

Research confirms that men are more interested in power, competition, and objects while women are more interested in relationships, cooperation, and people. The difference is already evident in new-borns, with girls maintaining eye-contact with adults longer than boys do. From infancy through old age, females are better at recognizing faces and at reading emotions on faces.

As soon as they can hold a crayon, boys and girls draw different things. In one study, when two- to four-year-olds were asked to draw illustrations for the same story, half of the girls put people in their pictures but fewer than one fifth of the boys did. Boys drew cars, trucks, or fire engines.

When they play, children segregate themselves by sex without any prompting from adults. The small number of boys who like to play with girls, and girls who like to play with boys are far more likely to be homosexual. The games that boys and girls play are different. Boys like games with elaborate rules and clear winners. Girls play relatively simple games cooperatively, and are much less interested in winning.

Differences in play resist strenuous environmental thwarting. No matter how hard they try, feminists cannot get most boys to play with dolls or girls to play with dump trucks. In pacifist households that ban toy guns, boys — but not girls — hold sticks up to their eyes and shout “bang, you’re dead.” Humans are similar to monkeys in that young females imitate their mothers by playing at child-rearing. Girls play with dolls and young female monkeys fondle babies and carry them about.

By the time they can be experimentally tested, males and females see the world differently. A machine called a tachistoscope shows a different image to each eye. When the images are shown very briefly, the brain perceives only the image it finds more interesting. Given a choice, males are more likely to see objects, and females are more likely to see people.

A greater interest in people and personal rapport is characteristic of most women. They are more likely to see their relations with others as a supportive network, whereas men measure themselves against each other and always want to know who is on top.

Differences of this kind may be reflected in the ways children learn. In school, boys learn pretty much the same amount of material, no matter whether the teaching style is competitive, cooperative, loose or strict. For girls, teaching style can make a big difference. It seems that boys are more likely to do whatever it is they are going to do, no matter how they are taught or influenced, whereas girls are more subject to the wishes and expectations of others.

Another male trait that starts early and lasts late is aggressiveness. Boys are already more active while they are still in the womb, and are strikingly more active than girls in elementary and junior high school. Boys’ play is more rambunctious than that of girls, just as young male monkeys are rougher than young females.

In all societies, men commit the vast majority of violent crimes. When women kill people, their victims are usually husbands, fathers, or boyfriends who, in some sense “deserved” it. Only men kill strangers and without provocation. Women attempt suicide more often than men, but men are much more likely to succeed at it.

The Role of Hormones

Mr. Pool explains that it is exposure to hormones that probably accounts for every one of the differences between the sexes. It has long been known that fertilized eggs most naturally and easily grow into females. It takes an elaborate conversion process — initiated by the Y (male) chromosome and controlled by the male hormone, testosterone — to make a male out of an essentially female substrate. The central role of testosterone in this process is clear from a study of people known as XY females, who suffer from an unusual but illuminating sexual condition.

Ordinarily, sex is determined at conception by the sperm. A child gets an X chromosome from its mother and either an X or a Y from its father. The father’s Y usually ensures that the child will be a boy — but not always. One out of every 20,000 genetic XY children has defective hormone receptors and is immune to the effects of testosterone. In the womb, these children develop testes, which produce testosterone, but it has no effect. Despite the fact that they are genetically male, they look like girls when they are born. Their underdeveloped testes are usually concealed in their labia, and no one would suspect that their vaginas lead to a dead end; they have no ovaries or uterus.

At puberty, these “girls” develop breasts and a woman’s body, but they do not menstruate. This may cause them to visit a doctor, who then discovers their strange condition. Their testes are usually removed because they are likely to become cancerous. Astonishingly, other than the fact that they cannot have babies, these people are and feel perfectly female. In fact, they tend to have glamorously long legs, large breasts, and clear skin. Many become fashion models. Mr. Pool reports that at least two well-known American movie actresses are XY women, who prefer to keep quiet about their condition.

XY women are often good at sports. Since the advent of genetic testing, they have been disqualified from international competitions, since they are genetically male. Mr. Pool argues that this is a mere technicality, and that they should be allowed to compete. In any case, these women — if that is what they are — are a startling demonstration of the triumph of hormones, not only over environment but even over genetics itself. If he is shielded from the all-important effects of testosterone, even a genetic male will grow up as a woman!

There is another strange condition, known as congenital adrenal hyperplasia (CAH), which is in some respects the opposite of that of XY women. CAH occurs in one of every 14,000 births and causes ordinary XX girls to be exposed to high levels of testosterone in the womb. In extreme cases, their external genitals are masculinized, but usually they are just girls who act like boys. They are aggressive, prefer trucks to dolls, and have better spatial abilities than other girls. They are also more likely to be lesbians. CAH girls, with their obviously masculine traits, are probably the best evidence available that it is nature rather than nurture that distinguishes the sexes. Parents may not even know their daughters have this condition, and rear them as girls. They still act like boys.

Merely having a male twin tends to somewhat masculinize girls. Compared to girls who have a female twin, those with male twins consistently score more like boys and men on tests that distinguish the sexes. Exposure to the boy twin’s testosterone in the womb is enough to change a baby girl for ever.

Of all the strange things that can happen to men and women, perhaps the strangest is to be physically and genetically one sex but feel like the opposite sex. This happens to about one in 12,000 men and about one in 30,000 women. Some get sex-change operations. Mr. Pool writes of one astonishing case in which a husband and wife both got sex changes and continued their marriage with the roles reversed. No one seems to know where the subjective feeling of sexual identity comes from, but hormones undoubtedly have something to do with it.

Hormones also appear to cause homosexuality. For men, not enough testosterone in the womb seems to be the cause, and for women, too much testosterone. Since genes control the level of testosterone in the womb, homosexuality runs in families. Male homosexuality, at any rate, appears to be passed through the mother.

As one might suspect, homosexuals’ spatial abilities are as bad as those of women. In childhood they typically do not like boys’ games and are thought of as sissies. Lesbians frequently start out as tomboys — as do many women who become politicians or corporate executives.

Although most of the work that hormones do is permanent (so long as they continue to be produced normally), there is one interesting exception. A woman’s hormone balance varies greatly according to her menstrual cycle and this affects some of her abilities. When female hormones are at high tide, a woman’s verbal skills improve and her sense of direction deteriorates. She becomes, in effect, more female.

Probing the Brain

Given that the sexes think and behave differently, it is no surprise to find that they have dissimilar brains. Of all the organs, the brain is the most complex and the least understood, so most research has been inconclusive. For example, it has been established that women have larger anterior commissures than men and that homosexuals have larger anterior commissures than women. No one, however, seems to know what the anterior commissure does.

Some research indicates that women parcel out mental activities to various parts of the brain while men keep the same activities concentrated in one place. There is also some evidence that the corpus callosum, which passes messages between brain hemispheres, is more developed in women than in men. Some people have theorized that the ability to put more parts of the brain to work on a problem accounts for “women’s intuition.”

The male brain is about five ounces heavier than the female brain, and this is not simply a reflection of greater body size. Even at age two or three, when boys are essentially the same size as girls, they have larger brains. There is a weak correlation between brain size and intelligence. For women, bigger brains are most strongly correlated with verbal IQ, and for men with spatial and mathematical ability.

Mr. Pool concedes that although men and women appear to have the same average intelligence, the variance among men is greater. He writes that no one disputes the well-established fact that there are more male than female idiots, but he calls the male preponderance in the high-IQ ranges “a touchy subject,” and quickly drops it. Likewise, although he explains that individual differences in IQ are largely genetic and that the environmental component seems to be some unknown factor that is neither family environment nor schooling, this is another fact that he treats as if it had no practical consequences. But what about sex differences?

Different But Equal

Here Mr. Pool lapses into incoherence. He concedes that men and women are different, but insists that they are nevertheless precisely, rigorously, mathematically equal. His book is full of earnest reassurances that sex research “may demonstrate that men and women are not the same, but never that they are not equal.” Research “shows that men’s and women’s brains are different, but it does not imply that one is better than the other.”

Mr. Pool tells us over and over that the sexes are not equal — in language, mathematics, spatial ability, motor control, brain size, aggressiveness, relations with people, memory, and a host of other things. And yet his concluding paragraph begins with the assertion that “the lesson of sex difference research is that men and women are different but still equal.” It is amusing how the liberal mind recoils from “separate but equal” but embraces an outright contradiction like “different but equal.”

Throughout the book, Mr. Pool treats the idea of the inherent equivalence of men and women with great reverence — as if it were the wisdom of the ages rather than the temporary insanity of a few decades. He writes of the danger of “misusing” this astonishing new information, and tries to reassure the startled reader by admitting that he, too, thinks the influence of hormones is “spooky.” He makes much of the fact that research on human sex differences is often done by liberal women who grew up in the 1960s — implying that this means we can trust them.

Sometimes he adopts the biased conceptions his entire book discredits. For example, he writes without qualification that girls are better at learning how to read. On the same page, he writes that boys are better at learning mathematics, “at least the way it’s taught in schools today.”

He regretfully concedes that even if “sexism” were completely extirpated, and boys and girls were treated identically, they would not turn out identically. But just what is “sexism,” anyway? Since boys and girls are inherently different, it is natural and proper to treat them differently. And why would anyone want boys and girls to turn out alike? Vive la difference! Why not encourage nature’s differences rather than try to suppress them? Mr. Pool is too tangled up in orthodoxy even to wonder.

It is easy to laugh at this book for its ideological blinders, but they do not change the importance of what it says. Current egalitarian hysteria usually requires that biological truths simply be suppressed.

We should therefore be grateful to Mr. Pool. Although he writes as if biology had few practical consequences, he at least writes about it. Most readers will remember what he says about sex differences long after they have forgotten his apologies for them.