by D. F. Swaab
As for mandatory anesthesia for fetuses in the case of abortion, one might argue that if it doesn’t benefit, it at least can’t harm, but abortion under a general anesthetic does increase the risk of complications for the mother. For the same reason, it would be greatly worrying if doctors were obliged to anesthetize fetuses undergoing interventions other than abortion, given that there’s no hard evidence that fetuses possess consciousness, whereas there is proof that anesthesia can impair a child’s later development.
From all this I conclude that in the case of abortions or interventions in utero up to the twenty-fifth or twenty-sixth week of pregnancy, a general anesthetic is unnecessary for the fetus and may entail extra risks for the mother, that a premature baby should be anesthetized before undergoing painful treatment just in case, and that it should be mandatory to anesthetize boys undergoing circumcision.
SAWING OFF YOUR OWN LEG: BODY INTEGRITY IDENTITY DISORDER, A BIZARRE DEVELOPMENTAL DISORDER
During our early development, not only is our gender identity and our sexual orientation programmed in our brains (see chapter 3) but the functioning of our inner body map is as well. Body Integrity Identity Disorder (BIID) is a bizarre developmental disorder of this latter process. Persons with this syndrome develop a belief early on that part of their body doesn’t belong to them, and they become desperate to get rid of it. They don’t accept a limb as being part of them, even though it functions perfectly. This leads to an overwhelming desire for amputation. Only when their arm or leg has been amputated—and around 27 percent of these individuals succeed in achieving this—do they feel “complete.” Surgeons who comply with these wishes run the risk of being fired for removing a healthy limb. That’s curious, because the principle being applied is similar to that used in the case of transsexuals and even circumcision. (Moreover, the latter operation is carried out on baby boys who are incapable of giving informed consent, and it can lead to complications like bleeding, infection, a perforated urethra, narrowing of the urethra, scarring, and malformation.) However, acceptance of the problems of BIID sufferers doesn’t seem to be coming any time soon. Psychotherapy or pills don’t on the whole change the sufferers’ way of thinking. There’s a sole recorded case of a BIID patient whose misery was alleviated by antidepressants and cognitive behavioral therapy, but he later declared that, although it was nice to talk to someone, the therapy had done nothing to resolve his BIID issue.
The conviction that a lower leg or arm doesn’t belong to them or the desire for paralysis of one or more limbs is something that affects these patients from an early age. A child with BIID cut dolls out of a magazine and then snipped off the leg that he himself didn’t want. BIID sufferers can even get excited or jealous when they see amputees or individuals suffering from the paralysis that they so long for. Sometimes it’s only then that they realize what they truly desire. They often pretend to be amputees, for instance by strapping their bent lower leg against their thigh, putting on wide trousers that hide the extra girth, folding the trouser leg back, and walking with crutches or sitting in a wheelchair. BIID patients often spend years trying to find a surgeon who will amputate their perfectly healthy, functioning limb. If this fails, which is usually the case, two-thirds of patients who ultimately undergo an amputation damage their unwanted limb to the extent that amputation becomes necessary. Sometimes they endanger their lives by shooting themselves through the knee, freezing their leg, or resorting to a saw. People with BIID are very specific about exactly where a limb should be amputated and have definite ideas as to whether the surgeon got it exactly right, but they are elated once they have had the operation, only regretting that it didn’t happen much earlier.
At present, it’s impossible to say exactly how the inner body map of such patients became flawed during the brain’s development. However, scans show that their frontal and parietal cortices respond differently to a touch on the leg according to whether it’s the accepted or the rejected leg. BIID shows similarities with transsexuality (see chapter 3). In both cases, a person knows—typically from an early age—that their body’s anatomy doesn’t tie in with how they feel. The link with transsexuality is particularly intriguing due to the high percentage of BIID patients (19 percent) who also have a gender identity problem, and the high percentage of homosexual and bisexual BIID patients (38 percent). Since all of these characteristics are programmed early in development, the same probably applies to BIID, though both its cause and location in the brain remain a mystery. There’s no reason at all to believe that BIID is caused by memories of a former life in which the person in question was missing a particular limb—as someone who wrote to me believed.
We have the technology to establish what has gone wrong in the body mapping function during the brain’s development. But for that to happen, doctors need to lose their fear of being involved in a patient’s desire for amputation. They have to stop dismissing them as “simply mad.” Researchers, for their part, need to look more closely at these strange variants that can increase our understanding of normal brain development. And, finally, people with BIID have to have the courage to come out of the closet in which many of them currently prefer to stay.
3
Sexual Differentiation of the Brain in the Womb
I am inclined to agree with Francis Galton in believing that education and environment produce only a small effect on the mind of anyone, and that most of our qualities are innate.
The Autobiography of Charles Darwin
My brain? That’s my second favorite organ.
Miles Monroe (Woody Allen) in Sleeper
A TYPICAL BOY OR GIRL?
Gender identity is sufficiently incompletely differentiated at birth as to permit successful assignment of a genetic male as a girl. Gender identity then differentiates in keeping with the experience of rearing.
J. Money, 1975
Nothing would seem simpler than seeing at birth whether a child is a boy or girl. After all, gender is determined from the moment of conception: Two XX chromosomes will become a girl, an X and a Y chromosome a boy. The boy’s Y chromosome starts the process that causes the male hormone testosterone to be produced. The presence or absence of testosterone makes the child develop male or female sex organs between the sixth and twelfth week of pregnancy. The brain differentiates along male or female lines in the second half of pregnancy, due to a male baby producing a peak of testosterone or a female baby not doing so. It’s in that period that the feeling of being a man or woman—our gender identity—is fixed in our brains for the rest of our lives.
That our gender identity is determined as early as in the womb has only been discovered fairly recently. Up to the 1980s it was thought that a child was born as a blank slate and that its behavior was then made male or female by social influences. This had huge consequences for the treatment of newborns with indeterminate sex organs in the 1960s and 1970s. It didn’t matter what sex you selected for your child, it was thought, as long as the operation took place soon after birth. The child’s surroundings would then ensure that its gender identity adapted to its sex organ. Only since then have patient associations revealed how many lives were ruined by assigning a sex on the operating table that didn’t match the gender identity imprinted in the brain before birth. The story of John-Joan-John shows how disastrous this approach could be. When a little boy (John) lost his penis at the age of eight months through a botched circumcision, it was decided to turn him into a girl (Joan). His testicles were removed while still an infant. He was dressed in girls’ clothes, received psychological counseling from John Money, a sexologist from Philadelphia, and was given estrogen during puberty. Money described the case as a great success: The child was said to have developed normally as a female (see the epigraph to this section). When I remarked during a seminar in the United States that this was the only case I knew showing that a child’s gender identity could be changed by its environment after birth, Milton Diamond, a renowned sexuality expert, stood up and said that Money’s
claim was completely unfounded. Diamond was acquainted with Joan; he knew that Joan had had his sex change reversed as an adult and had married and adopted children. Diamond made these findings public. Sadly, John later lost everything he had on the stock market, suffered an unhappy separation from his wife, and in 2004 committed suicide. This tragic story shows how strongly testosterone programs the brain in the womb. Removing this child’s penis and testicles, giving him psychological counseling, and administering estrogen during puberty couldn’t change his gender identity.
That testosterone is indeed responsible for causing sex organs and brains to develop along male lines is apparent from androgen insensitivity syndrome (AIS). People with this condition produce testosterone, but their bodies are insensitive to it. As a result, both the external sex organs and the brain are feminized. Even if they are genetically male (XY), they become heterosexual women. Conversely, in the case of girls who have been exposed to a high dose of testosterone in the womb due to congenital adrenal hyperplasia (CAH), the clitoris becomes so enlarged that they are sometimes registered as boys after birth. Almost all of these girls are assigned the female gender. But in 2 percent of cases it later emerges that they did in fact acquire a male gender identity in the womb.
The effect this can have in practice was shown clearly in a Dutch newspaper article by Jannetje Koelewijn (NRC Handelsblad, June 23, 2005). The parents of four daughters were overjoyed when their fifth child proved to be a boy. But after a few months the child fell ill, and it turned out to be a girl with CAH. Doctors talked at length with the parents, Turkish Muslims, who refused to consider gender reassignment, partly on religious grounds. So the doctors decided to make the child more like a boy. The clitoris was made larger, to resemble a penis, and the child was given hormones to promote masculine development. Its parents were delighted with the solution. But the brains of girls with CAH mostly develop along female lines. From the above data it seems extremely likely that the “little boy” will later experience gender problems and want to be a girl once more. When he enters puberty, he will also have to be told that he’s infertile, that he will need testosterone treatment for the rest of his life, and that his uterus and ovaries will have to be removed. The medical field now agrees that girls with CAH, even those who have become masculinized, should be raised as girls.
In those rare cases where a child’s sex is ambiguous and it’s uncertain whether its brain has masculinized or feminized, it can be assigned a temporary gender. Far-reaching interventions to turn such children into boys or girls should preferably be postponed until their gender identity has become clear through their behavior, although Katja Wolffenbuttel, a pediatric urologist working in Rotterdam, has shown that even operations can be reversed.
GENDER-BASED DIFFERENCES IN BEHAVIOR
Gender-based differences in the brain and in behavior are also found in areas that don’t appear to have a direct connection with reproduction. One of the stereotypical differences in behavior between boys and girls that’s often said to be socially conditioned is the way in which they play. Little boys are wilder and more active, preferring to play with cars or to pretend to be soldiers, while girls prefer to play with dolls. Because my observations of animals had left me with strong doubts about the social conditioning theory, when my children (a girl and a boy) were small, more than thirty years ago, my wife and I always would offer them both kinds of toys—but they were both very consistent in making stereotypical choices. Our daughter played only with dolls, while our son was interested only in toy cars. However, two children isn’t a big enough sample for proper research. That this difference has a biological basis was subsequently proven by Alexander and Hines, who offered dolls, toy cars, and balls to vervet monkeys. The female monkeys preferred the dolls, whose genitals they sniffed in a display of typical motherly behavior, while the male monkeys were much more interested in playing with toy cars and a ball. So toy preference isn’t forced on us by society, it’s programmed in our brains in order to prepare us for our roles in later life, namely motherhood in the case of girls and fighting and more technical tasks in the case of boys. The gender difference in the choice of toys by monkeys shows that its underlying mechanism goes back tens of millions of years in our evolutionary history. The peak in testosterone produced by boys in the womb appears to be responsible for this difference. Girls with CAH prefer to play with boys (and with boys’ toys) and are unusually boisterous, often getting labeled as tomboys.
There are also clear gender-based differences in the drawings that children make. Not only the subjects but also the colors and compositions of boys’ and girls’ drawings differ in ways that are influenced by hormones in the womb. Girls prefer to draw human figures, especially girls and women, as well as flowers and butterflies. They use bright colors like red, orange, and yellow. The compositions are peaceful, and the figures often stand on the same line. Boys, by contrast, prefer to draw mechanical objects, guns, conflict scenes, and vehicles like cars, trains, and planes. They often adopt a bird’s-eye view perspective and favor dark and cool colors like blue. Drawings done by five- and six-year-old girls with CAH resemble those of little boys, despite their being treated for their condition immediately after birth.
Some gender-based differences in our behavior emerge so early on that they can only have arisen in the womb. As early as the first day after birth, girl babies prefer to look at faces, while boy babies prefer to look at mechanical moving objects. At one year of age, girls already make more eye contact than boys, while girls exposed to too much testosterone in the womb make less eye contact later in childhood. So here, too, testosterone in the womb plays a key role. In daily life, eye contact has a very different significance for women and men. In Western culture, women use eye contact to understand other women better, and they find it satisfying. For Western men, however, the significance of eye contact lies in testing their place in the hierarchy, something that can feel very threatening. That too is pure biology. When you leave the airport in Aspen, Colorado, you come face-to-face with a warning sign reading, “If you meet a bear, don’t make eye contact.” The reason is that the bear will immediately attack to show who’s boss. My son carried out studies in the United States of the factors that determine success in negotiations. I’d once told him that in my experience, women negotiate differently than men. He wasn’t very interested at the time, but when he was in Chicago he suddenly decided to look into my theory. The experiments we subsequently carried out show that gender-based differences in eye contact also affect business transactions. Eye contact between two women during negotiation turns out to lead to a more creative outcome, while eye contact between two men actually prevents them from coming to terms. Men are handicapped by the threatening hierarchical implications of looking into someone’s eyes. Feel free to use this practical tip to your advantage.
HETEROSEXUALITY, HOMOSEXUALITY, AND BISEXUALITY
If a man lies with a male as he lies with a woman, both of them have committed an abomination. They shall surely be put to death.
Leviticus 20:13
[The] exclusive sexual interest felt by men for women is also a problem that needs elucidating and is not a self-evident fact based upon an attraction that is ultimately chemical in nature.
Sigmund Freud
Alfred Kinsey didn’t attract any notice when he published his doctoral thesis on gall wasps. But in 1948, when he produced the report Sexual Behavior in the Human Male and then, five years later, Sexual Behavior in the Human Female, he became a celebrity. He devised the “Kinsey scale,” which went from 0 to 6, 0 signifying exclusively heterosexual and 6 exclusively homosexual. Being bisexual, he himself would have been classified as a “Kinsey 3.”
A person’s position on the scale is determined in the womb by his or her genetic background and the effects of hormones and other substances on the developing brain. Studies of twins and families show that sexual orientation is 50 percent genetically determined, but the genes in question haven’t yet been iden
tified. It is curious that a genetic predisposition for homosexuality should persist in populations over the course of evolution, given that this group reproduces so much less. One explanation for why homosexuality persists is that the involved genes don’t just increase the likelihood of homosexuality but also promote fertility in the rest of the family. Heterosexual individuals with the same genes produce a larger than average number of offspring, causing the genes to remain in circulation.
Hormones and other chemical substances importantly affect the development of our sexual orientation. Girls with the adrenal gland disorder CAH who are exposed to high testosterone levels in the womb are more likely to become bisexual or homosexual. Between 1939 and 1960, around two million expectant mothers in the United States and Europe were prescribed the synthetic estrogen known as diethylstilbestrol (DES) in the belief that it would prevent miscarriages. (It didn’t, in fact, but doctors like to prescribe things, and patients are always keen to be treated.) DES turned out to increase the likelihood of bisexuality and homosexuality in the daughters of women given the drug. Pre-birth exposure to nicotine or amphetamines also increases the likelihood of lesbian daughters.
The more older brothers a boy has, the greater the chance that he will be homosexual. This is due to a mother’s immune response to male substances produced by boy babies in the womb, a response that becomes stronger with each pregnancy. Pregnant women suffering from stress are also more likely to give birth to homosexual children, because their raised levels of the stress hormone cortisol affect the production of fetal sex hormones.