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Chapter One

Ordained
By Nature
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Biology Constructs
the Sexes

A devil, a born devil, on whose nature Nurture can never stick! On whom my pains, Humanely taken, all, all lost, quite lost!

—WILLIAM SHAKESPEARE
THE TEMPEST

Oprah: "Do you think society will change if it were proven
beyond a shadow of a doubt that you were born that way?"

—THE OPRAH WINFREY SHOW

Aside from his exasperated cry of "women—what do they want?" Sigmund Freud's most famous line is probably the axiom "anatomy is destiny." Though it's not clear that Freud ever intended it to be taken literally, a large number of biologists believe that the differences in anatomy are decisive, and provide the basis for the differences in men's and women's experiences. One recent researcher proclaimed his belief that "the differences between the males and females of our species will ultimately be found in the cell arrangements and anatomy of the human brain." To biologists, the source of human behavior lies neither in our stars nor in ourselves, as Caesar had suggested to Brutus—but rather inour cells.

    Biological explanations hold a place of prominence in our explanations of both gender difference and gender inequality. For one thing, biological explanations have the ring of "true" science to them: Since their theories are based on "objective scientific facts," the arguments of natural scientists are extraordinarily persuasive. Secondly, biological explanations seem to accord with our own observations: Women and men seem so different to us most of the time—so different, in fact, that we often appear to be from different planets.

    There's also a certain conceptual tidiness to biological explanations, since the social arrangements between women and men (gender inequality) seem to stem directly and inevitably from the differences between us. Biological arguments reassure us that what is is what should be, that the social is natural. Finally, such reassurances tell us that these existing inequalities are not our fault, that no one is to blame, really. We cannot be held responsible for the way we act—hey, it's biological! (Such claims are made by conservatives and liberals, by feminists and misogynists, and by homophobes and gay activists.) What's more, if these explanations are true, no amount of political initiative, no amount of social spending, no great policy upheavals will change the relationships between women and men.

    This chapter will explore some of the various biological evidence that is presented to demonstrate the natural, biologically based differences between the sexes, and the ways in which social and political arrangements (inequality) directly flow from those differences. Biological differences can tell us much about the ways in which men and women behave. The search for such differences can also tell us a lot about our culture—about what we want so desperately to believe, and why we want to believe it.

Biological Differences, Then and Now
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The search for the biological origins of the differences between women and men is not new. What is new, at least for the past few centuries, is that scientists have come to play the central role in exploring the natural differences between males and females.

    Before the nineteenth century, most explanations of gender difference had been the province of theologians. God had created man and woman for different purposes, and those reproductive differences were decisive. Thus, for example, did the Rev. John Todd warn against woman suffrage that would "reverse the very laws of God" and its supporters who tried to convince women that she would "find independence, wealth and renown in man's sphere, when you only safety and happiness is patiently, lovingly, and faithfully performing the duties and enacting the relations of your own sphere."

    By the late nineteenth century, under the influence of Darwin and the emerging science of evolutionary biology, scientists jumped into the debate, wielding their latest discoveries. Some argued that women's normal biological processes made her unfit for the public world of work and school. For example, in his book A Physician's Counsels to Woman in Health and Disease (1871), Dr. W. C. Taylor cautioned women to stay home and rest for at least five or six days a month:

We cannot too emphatically urge the importance of regarding these monthly returns as periods of ill health, as days when the ordinary occupations are to be suspended or modified ... Long walks, dancing, shopping, riding and parties should be avoided at this time of month invariably and under all circumstances.

    In his path-breaking work, On the Origin of Species (1859), Darwin posed several questions. How do certain species come to be the way they are? Why is there such astonishing variety among those species? Why do some species differ from others in some ways and remain similar in other ways? He answered these questions with the law of natural selection. Species adapt to their changing environments. Those species that adapt well to their environments are reproductively successful, that is, their adaptive characteristics are passed on to the next generation, while those species that are less adaptive do not pass on their characteristics. Within any one species, a similar process occurs, and those individuals who are best suited to their environment pass on their genes to the next generation. Species are always changing, always adapting.

    Such an idea was theologically heretical to those who believed that God had created all species, including human beings, intact and unchanging. And Darwin did believe that just as the species of the lower animal world evidenced differences between males and females, so too did human beings. "Woman seems to differ from man in mental disposition, chiefly in her greater tenderness and lesser selfishness," he wrote in The Descent of Man. Men's competitiveness, ambition, and selfishness "seem to be his natural and unfortunate birthright. The chief distinction in the intellectual powers of the two sexes is shown by man's attaining to a higher eminence, in whatever he takes up, than can woman—whether requiring deep thought, reason, or imagination, or merely the uses of the senses and the hands."

    No sooner had the biological differences between women and men been established as scientific fact than writers and critics declared all efforts to challenge social inequality and discrimination against women to be in violation of the "laws of nature." Many writers argued that women's efforts to enter the public sphere—to seek employment, to vote, to enter colleges—were misguided for they placed women's social and political aspirations over the purposes for which their bodies had been designed. Women were not to be excluded from voting, from the labor force or from higher education as much as they were, as the Rev. Todd put it, "to be exempted from certain things which men must endure." This position was best summed up by a participant in a debate about woman suffrage in Sacramento, California, in 1880:

I am opposed to woman's sufferage [sic] on account of the burden it will place upon her. Her delicate nature has already enough to drag it down. Her slender frame, naturally weakened by the constant strain attendant upon her nature is too often racked by diseases that are caused by a too severe tax upon her mind. The presence of passion, love, ambition, is all too potent for her enfeebled condition, and wrecked health and early death are all too common.

    Social scientists quickly jumped on the biological bandwagon—especially Social Darwinists, who shortened the time span necessary for evolution from millennia to one or two generations and who causally extended his range from ornithology to human beings. In their effort to legitimate social science by allying it with natural law, Social Darwinists applied Darwin's theory in ways its originator had never imagined, distorting his ideas about natural selection to claim decisive biological differences among races, nations, families and, of course, between women and men. For example, the eminent French sociologist Gustav LeBon, who would later become famous for his theory of the collective mind and the irrationality of the crowd, believed that the differences between women and men could be explained by their different brain structure. He wrote in 1879:

In the most intelligent races, as among the Parisians, there are a large number of women whose brains are closer in size to those of gorillas than to the most developed of male brains.... All psychologists who have studied the intelligence of women ... recognize today that they represent the most inferior forms of human evolution and that they are closer to children and savages than to an adult civilized man. They excel in fickleness, inconstancy, absence of thought and logic, and incapacity to reason. Without doubt, there exist some distinguished women, very superior to the average man, but they are as exceptional as the birth of any monstrosity, as, for example, of a gorilla with two heads ...

    Much of the debate centered on whether or not women could be educated, especially in colleges and universities. One writer suggested that a woman "of average brain" could attain the same standards as a man with an average brain "only at the cost of her health, of her emotions, or of her morale." Another prophesized that women would grow bigger and heavier brains and their uteruses would shrink if they went to college. Perhaps the most famous social scientist to join this discussion was Edward C. Clarke, Harvard's eminent professor of education. In his best-selling book Sex in Education: or; A Fair Chance for the Girls (1873), Clarke argued that women should be exempted from higher education because of the tremendous demands made upon their bodies by reproduction. If women went to college, Clarke predicted, they would fail to reproduce, and it would require "no prophet to foretell that the wives who are to be mothers in our republic must be drawn from transatlantic homes." (Clarke's invocation of the threat to civilization posed by immigrants reproducing faster than native-born whites is common to the conflation of racism and sexism of the era.)

    The evidence for such preposterous biological claims? Simple. It turned out that college-educated women were marrying less often and bearing fewer children than noncollege-educated women. It must have been those shriveled wombs and heavier brains. And it also appeared that 42 percent of all women admitted to mental institutions were college-educated, compared with only 16 percent of the men. Obviously, collegiate education was driving women crazy. Today, of course, we might attribute this difference in fertility or in mental illness among college-educated women to enlarged opportunities or frustrated ambitions, respectively, but not to shrinking wombs. Clarke's assertions remain a striking example of the use of correlational aggregate social science data for decidedly political purposes.

    The implicit conservatism of such arguments was as evident at the turn of the last century as it is now. "How did woman first become subject to man as she is now all over the world?" asked James Long. "By her nature, her sex, just as the negro is and always will be, to the end of time, inferior to the white race, and therefore, doomed to subjection; but happier than she would be in any other condition, just because it is the law of her nature."

    Today, biological arguments generally draw their evidence from three areas of research: (1) evolutionary theory, from sociobiology to "evolutionary psychology"; (2) brain research; and, (3) endocrinological research on sex hormones, before birth and again at puberty. The latter two areas of research are also used to describe the biologically based differences between heterosexuals and homosexuals, which are, as we shall see, often expressed in gender terms.

The Evolutionary Imperative: From Social Darwinism to Sociobiology
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Evolutionary biologists since Darwin have abandoned the more obviously political intentions of the Social Darwinists, but the development of a new field of sociobiology in the 1970s revived evolutionary arguments again. Edward Wilson, a professor of entomology at Harvard, helped to found this school of thought, expanding his original field of expertise to include human behavior as well as bugs. All creatures, Wilson argued, "obey" the "biological principle," and all temperamental differences (personalities, cultures) derive from the biological development of creatures undergoing the pressure of evolutionary selection. The natural differences that result are the source of the social and political arrangements we observe today. As Wilson and fellow psychobiologist Richard Dawkins put it, "[F]emale exploitation begins here." Culture has little to do with it, as Wilson argues, for "the genes hold culture on a leash."

    One of the major areas that sociobiologists have stressed is the differences in male and female sexuality, which they believe to be the natural outgrowth of centuries of evolutionary development. Evolutionary success requires that all members of a species consciously or unconsciously desire to pass on their genes. Thus males and females develop reproductive "strategies" to ensure that our own genetic code passes on to the next generation. Sociobiologists often use a language of intention and choice, referring to "strategies" that makes it sound as if our genes were endowed with instrumental rationality, and each of our cells acted in a feminine or masculine way. Thus they seem to suggest that the differences we observe between women and men today have come from centuries of advantageous evolutionary choices.

    Take, for example, the size and the number of the reproductive cells themselves. Add to that the relative cost to male and female in producing a healthy offspring, and—presto!—you have the differences between male and female sexual behavior at a typical college mixer this coming weekend. "He" produces billions of tiny sperm; "she" produces one relatively gigantic ovum. For the male, reproductive success depends upon his ability to fertilize large numbers of eggs. Toward this end, he tries to fertilize as many eggs as he can. Thus, males have a "natural" propensity toward promiscuity. By contrast, females require only one successful mating before their egg can be fertilized, and therefore they tend to be extremely choosy about which male will be the lucky fellow. What's more, females must invest a far greater amount of energy in gestation and lactation, and have a much higher reproductive "cost," which their reproductive strategies would reflect. Females, therefore, tend to be monogamous, choosing the male who will make the best parent. "A woman seeks marriage to monopolize not a man's sexuality, but, rather, his political and economic resources, to ensure that her children (her genes) will be well provided for," writes journalist Anthony Layng. As psychobiologist Donald Symons puts it, women and men have different "sexual psychologies":

Since human females, like those of most animal species, make a relatively large investment in the production and survival of each offspring—and males can get away with a relatively small one—they'll approach sex and reproduction, as animals do, in rather different ways from males.... Women should be more choosy and more hesitant, because they're more at risk from the consequences of a bad choice. And men should be less discriminating, more aggressive and have a greater taste for variety of partners because they're less at risk.

Not surprisingly, Symons notes, this is "what we find":

Selection favored the basic male tendency to be aroused sexually by the sight of females. A human female, on the other hand, incurred an immense risk, in terms of time and energy, by becoming pregnant, hence selection favored the basic female tendency to discriminate with respect both to sexual partners and to the circumstances in which copulation occurred.

    The dilemma for these monogamous females, then, is how to extract parental commitment from these recalcitrant rogue males, who would much prefer to be out fertilizing other females than home with the wife and kids. Her strategy is to "hold out" for emotional, and therefore parental, commitment before engaging in sexual relations. Thus women are not only predetermined to be monogamous, but they also link sexual behavior to emotional commitment, extracting from those promiscuous males all manner of promises of love and devotion before they will finally "put out." Thus males are hardwired genetically to be promiscuous sexual predators, ever on the prowl for new potential sexual conquests, while females have a built-in biological tendency toward monogamy, fantasies of romantic love and commitment coupled with sexual behavior, and a certain sexual reticence that can only be activated by chivalric male promises of fealty and fidelity.

    Other evolutionary arguments examine other aspects of reproductive biology to spell out the differences between men and women, and thereby explain the social inequality between them. For example, the separation of spheres seems to have a basis far back in evolutionary time. "In hunter-gatherer societies, men hunt and women stay at home. This strong bias persists in most agricultural and industrial societies, and, on that ground alone, appears to have a genetic origin, writes Edward Wilson. "My own guess is that the genetic bias is intense enough to cause a substantial division of labor in the most free and most egalitarian of future societies."

    Lionel Tiger and Robin Fox emphasize the social requirements for the evolutionary transition to a hunting and gathering society. First, the hunting band must have solidarity and cooperation, which requires bonding among the hunters. Women's biology—especially their menstrual cycle—puts them at a significant disadvantage for such consistent cooperation, while the presence of women would disrupt the cooperation necessary among the men and insinuate competition and aggression. They also are possessed of a "maternal instinct." Thus, it would make sense for men to hunt, and for women to remain back home raising the children.

    From such different reproductive strategies and evolutionary imperatives come different temperaments, the different personalities we observe in women and men. The newest incarnation of sociobiology is called "evolutionary psychology," which declares an ability to explain psychological differences between women and men through their evolutionary trajectories. Men are understood to be more aggressive, controlling, and managing—skills that were honed over centuries of evolution as hunters and fighters. After an equal amount of time raising children and performing domestic tasks, women are said to be more reactive, more emotional, and more passive.

    Finally, these differences also enable scientists to try and explain such behaviors as interspecies violence and aggression. Psychobiologist David Barash combines sociobiology with New Age platitudes when he writes that "genes help themselves by being nice to themselves." Unfortunately, this doesn't necessarily mean being nice to others. Selfish genes do not know the golden rule. For example, Barash explains rape as a reproductive adaptation by men who otherwise couldn't get a date. Following their study of scorpion flies and mallard ducks, Barash, Thornhill, and other evolutionists argue that men who rape are fulfilling their genetic drive to reproduce in the only way they know how. "Perhaps human rapists, in their own criminally misguided way, are doing the best they can to maximize their fitness," writes Barash. Rape, for men, is simply an "adaptive" reproductive strategy for the less successful male—sex by other means. If you can't pass on your genetic material by seduction, then pass it on by rape.

    Don't blame the men, though—or even their genetic imperatives. It's really women's fault. "As females evolved to deny males the opportunity to compete at ovulation time, copulation with unwilling females became a feasible strategy for achieving copulation," write Richard Alexander and K. M. Noonan. If women were only a bit more compliant, it would seem, men wouldn't be forced to resort to rape as a reproductive tactic.

Sociobiology—A "Just—So" Story
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Do these evolutionary arguments make sense? Does their evidence add up to basic, irreconcilable differences between women and men, made necessary by the demands of evolutionary adaptation? While there is a certain intuitive appeal to these arguments—since they give our contemporary experiences the weight of history and science—there are simply too many convenient lapses in reasoning for us to be convinced.

    The theory may tidily describe the intricate mating rituals of fruit flies or brown birds, or seem applicable to an urban singles bar or the dating dynamics of high school and college students, but it is based on an interpretation of evidence that is selective, and conforms to preconceived ideas It is as if these sociobiologists observe what is normative—that men are more likely than women to separate love and sex, that men feel entitled to sexual contact with women, that men are more likely to be promiscuous—and read it back into our genetic coding. Such explanations always fall into teleological traps, reasoning backward to fill existing theoretical holes. It is so because it is supposed to be so. Besides, the time span is too short. Can we explain each single sexual encounter by such grand evolutionary designs? I would bet that most of our conscious "strategies" at college mixers have more immediate goals than to ensure our reproductive success.

    Some arguments go far beyond what the data might explain and into areas that are empirically untestable. Biologist Richard Lewontin, a passionate critic of sociobiology, argues that, "no evidence at all is presented for a genetic basis of these characteristics [religion, warfare, cooperation] and the arguments for their establishment by natural selection cannot be tested, since such arguments postulate hypothetical situations in human prehistory that are uncheckable." And fellow evolutionary biologist Stephen Jay Gould denies that there is "any direct evidence for genetic control of specific human social behavior."

    Some sociobiological arguments seem to assume that only one interpretation is possible from the evidence. But there could be others. Psychologists Carol Tavris and Carole Wade, for example, ask why parents—women or men—would "invest" so much time and energy in their children when they could be out having a good time? While sociobiologists argue that we are hardwired for such altruistic behavior, because our children are the repository of our genetic material, Tavris and Wade suggest that it may be simple economic calculation: In return for taking care of our offspring when they are young and dependent, we expect them to take care of us when we are old and dependent—a far more compact and tidy explanation.

    Some sociobiological arguments are based on selective use of data, ignoring those data that might be inconvenient. Which species should we use as the standard of measurement? Among chimpanzees and gorillas, for example, females usually leave home and transfer to new tribes, leaving the males at home; among baboons, macaques, and langurs, however, it's the males who leave home to seek their fortune elsewhere. So which sex has the wanderlust, the natural predisposition to leave home? Sociobiologists tend to favor male-dominant species to demonstrate the ubiquity of male dominance. But there are other species. For example, baboons seem to be female-dominant, with females determining the stability of the group and deciding which males are trustworthy enough to be their "friends." Then there is the female chimpanzee. She has sex with lots of different males, often up to 50 times a day during peak estrus. She flirts, seduces, and does everything she can to attract males—who she then abandons and moves on to the next customer. Would we say that such evidence demonstrates that females are genetically programmed toward promiscuity and males toward monogamy? And sociobiologists tend to ignore other behavior among primates. For example, sexual contact with same-sex others is "part of the normal sexual repertoire of all animals, expressed variously over the lifetime of an individual." But few posit a natural predisposition toward homosexuality.

    Some arguments are just plain wrong in light of empirical evidence. Take the argument about how women's menstrual cycle debilitates them so that they were inevitably and correctly left behind in the transition to hunting and gathering. Katherina Dalton's research on English schoolgirls showed that 27 percent got poorer test scores just before menstruation than at ovulation. (She does not say how much worse they did.) But 56 percent showed no change in test grades and 17 percent actually performed better at premenstruation. And what about that "maternal instinct"? How do we explain the enormous popularity of infanticide as a method of birth control throughout Western history, and the fact that it was women who did most of the baby killing? Infanticide has probably been the most commonly practiced method of birth control throughout the world. One historian reported that infanticide was common in ancient Greece and Rome and that "every river, dung heap and cesspool used to be littered with dead infants." In 1527, a priest commented that "the latrines resound with the cries of children who have been plunged into them."

    And finally, what is one to make of the argument that rape is simply sex by other means for reproductively unsuccessful males? Such arguments ignore the fact that most rapists are not interested in sex but in humiliation and violence, motivated more by rage than by lust. Most rapists have regular sex partners, quite a few are married. Many women well outside of reproductive age, either too young or too old, are raped. And why would some rapists hurt and even murder their victims, thus preventing the survival of the very genetic material that they are supposed to be raping in order to pass on? And why would some rapists be homosexual rapists, passing on their genetic material to those who could not possibly reproduce? And what about rape in prison? Using theories of selfish genes or evolutionary imperatives to explain human behavior cannot take us very far.

    Sociobiology and evolutionary psychology provide us with what Rudyard Kipling called a "just-so story"—an account that uses some evidence to tell us how, for example, an elephant got its trunk, or a tiger its stripes. These are children's fables, understood by the reader to be fictions, but convenient, pleasant and, ultimately, useful fictions.

    Could we not use the same evidence and construct a rather different "just-so" story? Try this little thought experiment. Let's take the same evidence about sperm and eggs, about reproductive strategies, about different levels of parental investment that the sociobiologists use, add a few others, and see what happens. Let's also remember that human females are the only primate females who do not have overtly signalled estrus—that is, they are potentially sexually receptive at any time of their reproductive cycle, including when they are incapable of conception. What could be the evolutionary reproductive "strategy" of this? And let's also remember that the human clitoris plays no part whatsoever in human reproduction, but is solely oriented toward sexual pleasure. And finally, let's not forget that when a baby is born, the identity of the mother is obvious, though that of the father is not. Until very recently, with the advent of DNA tests, fathers could never be entirely certain that the baby was theirs; after all, how do they know their partner had not had sexual contact with another male?

    From this evidence one might adduce that human females are uniquely equipped biologically—indeed, that it is their sexual strategy—to enjoy sex simply for its physical pleasure and not for its reproductive potential. And if the reproductive goal of the female is to ensure the survival of her offspring, then it would make sense for her to deceive as many males as possible into thinking that the offspring was theirs. That way, she could be sure that all of them would protect and provide for the baby, since none of them could risk the possibility of his offspring's death and the obliteration of his genetic material. So might not women's evolutionary "strategy" be promiscuity?

    Another biological fact about women might make life even more confusing for males seeking to determine paternity. Barbara McClintock's research about women's menstrual cycles indicated that in close quarters, women's cycles tended to become increasingly synchronous; that is, over time, women's cycles will tend to converge with those of their neighbors and friends. (McClintock noticed this among her roommates and friends while an undergraduate at Harvard in the early 1970s.) What's more, in cultures where artificial light is not used, all the women will tend to ovulate at the full moon and menstruate at the new moon. While this might be an effective method of birth control in nonliterate societies (to prevent pregnancy, you must refrain from sex when the moon approaches fullness), it also suggests that unless women were controlled, paternity could not be established definitively.

    If males were as promiscuous as females they would end up rather exhausted and haggard from running around hunting and gathering for all those babies who might or might not be their own. How were they to know, after all? In order to ensure that they did not die from exhaustion, males might "naturally" tend toward monogamy, extracting from women promises of fidelity before offering up a lifetime of support and protection to the potential offspring from those unions. Such males might invent ideals of female chastity, refuse to marry (sexually commit to) women who were not virgins, and develop ideologies of domesticity that would keep women tied to the household and children to prevent them from indulging in their "natural" disposition towards promiscuity.

    Of course, I'm not suggesting that this interpretation supplant the one offered by evolutionary psychologists. But the fact that one can so easily use the exact same biological evidence to construct an entirely antithetical narrative suggests that we should be very careful when the experts tell us there is only one interpretation possible from these facts.

"His" Brain and "Her" Brain
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Biologists have also focused on the brain to explain the differences between women and men. This approach, too, has a long history. In the eighteenth century, experts measured women's brains and men's brains and argued that, since women's brains were smaller and lighter, they were inferior. Of course, it later turned out that women's brains were not smaller and lighter relative to body size and weight, and thus were not predictive of any cognitive differences. The late nineteenth century was the first heyday of brain research, as researchers explored that spongy and gelatinous three-pound blob in order to discover the differences between whites and blacks, Jews and non-Jews, immigrants and "normal" or "real" Americans, criminals and law-abiding citizens. For example, one researcher at the turn of the century argued that the brain of the average "grown-up Negro partakes, as regards his intellectual faculties, of the nature of the child, the female, and the senile White." (One can only speculate where this put older black women.) But despite the fact that none of these hypothesized differences turned out to have any scientific merit, they all satisfied political and racist assumptions.

    Brain research remains a particularly fertile field of study and scientists continue their search for differences between women and men in their brains. One writes that "many of the differences in brain function between the sexes are innate, biologically determined, and relatively resistant to change through the influences of culture." Popular books proclaim just how decisive these differences are. The male brain is "not so easily distracted by superfluous information"; it is a "tidier affair" than the female brain, which appears "less able to separate emotion from reason." (Notice that these statements did not say—though they easily might have, based on the same evidence—that the female brain is capable of integrating more diverse sources of information and better able to synthesize feelings and thought.)

    That brain research fits neatly (a male brain trait?) into preconceived ideas about men's and women's roles is hardly a coincidence. In most cases, brain researchers (like many other researchers) find exactly what they are looking for, and what they are looking for are the brain-based differences that explain the observable behavioral differences between adult women and men. One or two historical examples should suffice. The "science" of craniology was developed in the late nineteenth century to record and measure the effect of brain differences among different groups. But the scientists could never agree on exactly which measures of the brain to use. They knew that men's brains had to be shown to be superior, but different tests yielded different results. For example, if one used the ratio of brain surface to body surface, then men's brains would "win"; but if one used the ratio of brain weight to body weight, women's brains would appear superior. No scientist could rely on such ambiguity: More decisive methods had to be found to demonstrate that men's brains were superior.

    Test scores were no better as indicators. At the turn of the century, women were found to be scoring higher on comprehensive examinations at New York University. Since scientists "knew" that women were not as smart as men, some other explanation had to be sought. "After all, men are more intellectual than women, examination papers or no examination papers," commented the dean of the college, R. Turner. "Women have better memories and study harder, that's all. In tasks requiring patience and industry women win out. But when a man is both patient and industrious he beats a woman any day." (It is interesting to see that women's drive, ambition, and industriousness are used against them, rather then labeling the problem as men's impulsiveness, impatience, and laziness.) In the 1920s, when IQ tests were first invented, women scored higher on those tests as well. So the experimenters changed the questions.

    Contemporary brain research has focused on three areas: (1) the differences between right and left hemisphere; (2) the differences in the tissue that connects those hemispheres; and (3) the ways in which males and females use different parts of their brains for similar functions.

    Some scientists have noticed that the right and left hemispheres of the brain seem to be associated with different cognitive functions and abilities. Right-hemisphere dominance is associated with visual and spatial abilities, such as the ability to conceive of objects in space. Left-hemisphere dominance is associated with more practical functions, such as language and reading. Norman Geschwind and Peter Behan, for example, observed that sex differences begin in the womb when the male fetus begins to secrete testosterone that washes over the brain, selectively attacking parts of the left hemisphere and slowing its development. Thus, according to Geschwind, males tend to develop "superior right hemisphere talents, such as artistic, musical, or mathematical talent." Geschwind believes that men's brains are more lateralized, with one half dominating over the other, while women's brains are less lateralized, with both parts interacting more than in men's.

    One minor problem with this research, though, is that scientists can't seem to agree on which it is "better" to have and, not so coincidentally, which side of the brain dominates for which sex. In fact, they keep changing their minds about which hemisphere is superior, and then, of course, assigning that superior one to men. Originally, it was the left hemisphere that was supposed to be the repository of reason and intellect, while the right hemisphere was the locus of mental illness, passion, and instinct. So males were thought to be overwhelmingly more left-brained than right-brained. By the 1970s, though, scientists had determined that the truth lay elsewhere, and that the right hemisphere was the source of genius, talent, creativity and inspiration, while the left brain was the site of ordinary reasoning, calculation, and basic cognitive function. Suddenly males were hailed as singularly predisposed towards right-brained-ness. One neuroscientist, Ruth Bleier, reanalyzed Geschwind and Behan's data and found that in over five hundred fetal brains from ten to forty-four weeks of gestation, the authors had found no significant sex differences—this despite the much-trumpeted testosterone bath.

    Perhaps it wasn't which half of the brain dominates, but the degree to which the brain was lateralized—that is, had a higher level of differentiation between the two hemispheres—that determined sex differences. Buffery and Gray found that female brains were more lateralized than male brains, which, they argued, interfered with spatial functioning, and made women less capable at spatial tasks. That same year, Levy found that female brains were less lateralized than male brains, and so he argued that less lateralization interferes with spatial functioning. (There is virtually no current evidence for either of these positions, but that has not stopped most writers from believing Levy's argument.)

    If that tack wasn't successful, scientists reasoned, perhaps both males and females use both halves of their brains, but use them differently. In their popular book detailing these brain differences, Jo Durden-Smith and Diane deSimone suggest that in the female left hemisphere, language tends to serve as a vehicle for communication, whereas for males it is a tool for more visual-spatial tasks, like analytical reasoning. Similarly, they argue, in the right hemisphere males assign more neural space to visual-spatial tasks, while females have more room left over for other types of nonverbal communication skills, such as emotional sensitivity and intuition.

    But don't the differences in mathematical ability and reading comprehension provide evidence of different sides of the brain being more dominant among females and males? While few would dispute that different sides of the brain account for different abilities, virtually all humans, both men and women, use both sides of their brains to reasonably good effect. If so, argues the neuropsychiatrist Jerre Levy, "then males may be at a double disadvantage in their emotional life. They may be emotionally less sophisticated. And because of the difficulty they may have in communicating between their two hemispheres, they may have restricted verbal access to their emotional world."

    It is true that males widely outnumber females at the genius end of the mathematical spectrum. But does that mean that males are, on average, more mathematically capable and females more verbally capable? Janet Hyde, a psychologist at the University of Wisconsin, has conducted a massive amount of research on this question. She reviewed 165 studies of verbal ability that included information about over 1.4 million people and included writing, vocabulary, reading comprehension. She found no gender differences in verbal ability. But when she analyzed one-hundred studies of mathematical ability, representing the testing of nearly four million students, she did find some modest gender differences. In the general studies, females outperformed males in mathematics, except in those studies designed only for the most precocious individuals. What Hyde and her colleagues—and virtually every single study ever undertaken—found is that there is a far greater range of differences among males and among females than there is between males and females. That is to say that the variance within the group far outweighs the variance between groups, despite the possible differences between the mean scores of the two groups.

    But what if it's not the differences between the hemispheres, or even that males and females use the same hemispheres differently? Perhaps it's the connections between the hemispheres. Some researchers have explored the bundle of fibers known as the corpus collosum that connect the two hemispheres and carry information between them. A subregion of this connecting network, known as the splenium, was found by one researcher to be significantly larger and more bulbous in shape in females. This study of fourteen brains at autopsy suggested that this size difference reflected less hemispheric lateralization in females than in males, and that this affected visual and spatial functioning. But subsequent research failed to confirm this finding. One researcher found no differences in the size of the corpus callosum between males and females. What's more, in magnetic resonance imaging (MRI) tests on living men and women, no differences were found between women and men.

    But that doesn't stop some popular writers from dramatic and facile extrapolation. Here's Robert Pool, from his popular work, Eve's Rib: "Women have better verbal skills than men on average; the splenium seems to be different in women and men, in shape if not in size; and the size of the splenium is related to verbal ability, at least in women." In fact, there seems to be little consistent evidence for significant brain differences between women and men. Jonathan Beckwith, professor of microbiology and molecular genetics at Harvard Medical School argues that "[e]ven if they found differences, there is absolutely no way at this point that they can make a connection between any differences in brain structure and any particular behavior pattern or any particular aptitude."

    If there is no evidence of these arguments, why do they persist? One brain researcher, Marcel Kinsbourne suggests that it is "because the study of sex differences is not like the rest of psychology. Under pressure from the gathering momentum of feminism, and perhaps in backlash to it, many investigators seem determined to discover that men and women 'really' are different. It seems that if sex differences do not exist, then they have to be invented."

The Gay Brain
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One of the most interesting and controversial efforts by scientists who study the biological origins of behavior has been the search for biological origins of sexual orientation. Recent research on brain structure and endocrinological research on hormones has suggested a distinctly homosexual "essence," which will emerge regardless of the cultural conditions that shape its opportunities and experiences. This research on the origins of sexual orientation is related to research on the basis of sex differences between women and men because, culturally, we tend to understand sexuality in terms of gender. Gender stereotypes dominate the discussion of sexual orientation; we assume, for example, that gay men are not "real" men—that is, that they are not sufficiently masculine, identify with women, and even adopt feminine affect and traits. Similarly, we may assume that lesbians are insufficiently feminine, identify with and imitate men's behaviors, and so on. Homosexuality, our stereotypes tell us, is a gender "disorder."

    We have a century-long historical legacy upon which we draw such stereotypic ideas. Homosexuality emerged as a distinct identity in the late nineteenth century, when it was regarded as an "inborn, and therefore irrepressible drive" according to one Hungarian physician. Earlier, there were homosexual behaviors, of course, but identity did not emerge from nor inhere in those behaviors. By the turn of the century, though, "the homosexual" was characterized by an form of "interior androgyny, a hermaphroditism of the soul," writes Foucault. "The sodomite had been a temporary aberration; the homosexual was now a species." Since Freud's era, we have assumed that male homosexuality, manifested by effeminacy, and lesbianism, manifested by masculine affect, might not be innate, but were, nonetheless, intractable products of early childhood socialization, and that differences between gays and straights, once established, proved the most telling in their lives' trajectories.

    In recent decades, biological research has emerged as central in the demonstration of the fundamental and irreducible differences between homosexuals and heterosexuals. And, it should not surprise us that researchers have found what they hoped to find—that homosexual men's brains and hormone levels more closely resemble those of females than those of heterosexual males. Science, again, has attempted to prove that the stereotypes of gay men and lesbians are based not in cultural fears and prejudices, but in biological fact. For example, in the 1970s, Dorner and his associates found that homosexual men possess a "predominantly female-differentiated brain" caused by a "deficiency" of androgen during the hypothalamic organizational phase in prenatal life, and which may be activated to homosexual behavior by normal or about-normal androgen levels in adulthood.

    More recently, Simon LeVay focused on the structure of the brain in an effort to uncover the etiology of homosexuality. LeVay gives no credence to environmental determination of sexuality. "If there are environmental influences, they operate very early in life, at the fetal or early-infancy stages, when the brain is still putting itself together," he argues. "I'm very much skeptical of the idea that sexual orientation is a cultural thing." LeVay noticed that, among primates, experimental lesions in the medial zone of the hypothalamus did not impair sexual functioning, but did suppress mounting attempts by the male monkeys on female monkeys. He also noticed that the size of this region of the brain was different in men and women. In his experiment, LeVay examined the brain tissues of forty-one deceased people. Nineteen of these had died of AIDS and were identified as part of the risk group "homosexual and bisexual men"; sixteen other men were presumed to be heterosexual because there was no evidence to the contrary (six had died of AIDS and the other ten from other causes); and six were women who were presumed heterosexual (one had died of AIDS). These brains were treated and compared. Three of the four sections revealed no differences, but a fourth section, the anterior hypothalamus, a region about the size of a grain of sand, was found to be different among the groups. LeVay found that the size of this area among the presumably heterosexual men was approximately twice the size of that area for the women and the presumably gay men.

    But several problems in his experiments give us pause. LeVay and his colleagues failed to measure the cell number or density because "of the difficulty in precisely defining the neurons belonging to INAH 3," the area of the brain involved. A number of the "homosexual" men (five of the nineteen) and of the women (two of the six) appeared to have areas of the brain as large as those of the presumed heterosexual men. And in three of the presumed heterosexual men, this area of the brain was actually very small. What's more, the sources of his data were widely varied. All the gay men in his sample died of AIDS, a disease known to affect the brain. And all the brains of gay men were preserved in a formaldehyde solution that was of a different strength of the solution in which the brains of heterosexual men were preserved, because of the fears of HIV transmission, although there was no effort to control for the effect of the formaldehyde on the organs. It is possible that what LeVay may have been measuring was the combined effect of HIV infection and preservation in high densities of formaldehyde solution on postmortem brain structure, rather than differences in brain structure between living heterosexuals and homosexuals. A recent effort to replicate LeVay's findings failed, and one researcher went further suggesting that "INAH-3 is not necessary for sexual behavior in men, whether they chose men or women as their partners."

    More recently, researchers have found that the brains of male transsexuals more closely resembled the brains of women than heterosexual, "normal" men. Dutch scientists at the Netherlands Institute for Brain Research examined the hypothalamus sections of forty-two men and women, six of whom were known to be transsexuals, and nine of whom were gay men, while the rest were presumed to be heterosexual. Again they found that the hypothalamus in the transsexual men and women was smaller than in those of the heterosexual or homosexual men. While they were careful not to interpret their findings in terms of sexual orientation, since the heterosexual and homosexual men's brains were similar, they did take their research to signal sex differences, since the male transsexuals were men who felt themselves to be women. However, it may also be a result of transsexual surgery and the massive amounts of female hormones taken by the male transsexuals, which might have had the effect of shrinking the hypothalamus, just as the surgery and hormones also resulted in other anatomical changes (loss of facial and body hair, breast growth, etc.).

    And the "evidence" keeps pouring in. As I write comes a new revelation about the biological origins of sexual orientation. One ear researcher found that the sounds emitted by the inner ears of lesbians "work more like those of men," because they have "less sensitive cochlea amplifiers" than those of heterosexual women. Apparently, heterosexual women's ears emit a wider range of sounds—and I would presume they're also higher pitched. Personally, I'm more concerned about the sounds of bias and false difference that flow into our ears than the sounds that come out of them.

The Search for the Gay Gene
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Other biological research has attempted to isolate a gay gene, and thus show that sexual orientation has its basis in biology. For example, research on pairs of monozygotic twins (twins born from a single fertilized egg that splits in utero) suggests that identical twins have a statistically far higher likelihood of having similar sexualities (either both gay or both straight) than dizygotic twins (twins born from two separate fertilized eggs). One genetic study involved eighty-five pairs of twins in the 1940s and 1950s. All forty pairs of monozygotic twins studied shared the same sexual orientation; if one twin was heterosexual, the other was also; if one twin was homosexual, so too was the other twin. Such data were so perfect that subsequent scientists have doubted their validity.

    More recently, Eckert and his colleagues found that in fifty-five pairs of twins, five had at least one gay member, and in a sixth, one twin was bisexual. Bailey and Pillard collected data on gay men who were twins, as well as on gay men who had adoptive brothers who lived in the same home before age two. The 161 respondents were drawn from responses to ads placed in gay periodicals and included fifty-six monozygotic twins, fifty-four dizygotic twins, and fifty-seven adoptive brothers. Respondents were asked about their brothers' sexuality and were asked permission to contact those brothers. About three-fourths of the brothers participated in the study. Bailey and Pillard found that in 52 percent of the monozygotic pairs, and in 22 percent of the dizygotic pairs, and in 11 percent of the adoptive pairs, both brothers were homosexual or bisexual.

    Such findings suggest that there may be some biological foundation for men's sexual contact with other men. But several problems remain. The study was generated from self-identified homosexuals, not from a sample of twins. What's more, there was no independent measure of the environment in which these boys grew up, so that what Bailey and Pillard might have measured is the predisposition of the environments to produce similar outcomes among twins. After all, biological predisposition should be more compelling than one-half.

    There is some evidence that homosexual orientations tend to occur more frequently in family constellations. Psychiatrist Richard Pillard and psychologist James Weinrich questioned fifty heterosexual men and fifty-one homosexual men and their siblings. Only 4 percent of the heterosexual men had brothers who were homosexual (the same percentage that had been found by Kinsey's studies in the 1940s), while about 22 percent of the gay men had gay or bisexual brothers. "This is rather strong evidence that male homosexuality clumps in families," said Weinrich, although there was no indication of the biological or genetic origin of this relationship. And the correlation, incidentally, did not hold true for women, as about the same percentage of the sisters of both groups said they had sisters who were lesbian. None said either of his or her parents was gay. This gender disparity might suggest that more than biology is at work here, and that gender identity may have more to do with inequality than with genetics.