We Are Our Brains

by D. F. Swaab

  Pedophilia can have different causes. If an adult suddenly experiences pedophilic urges, they may have a brain tumor in the prefrontal cortex, temporal cortex, or hypothalamus. Sometimes it is a symptom of dementia. A sudden switch in sexual inclination to pedophilia has also been caused by operations to cure epilepsy by removing part of the anterior temporal lobe. Such patients can go on to develop Klüver-Bucy syndrome, which involves the loss of sexual inhibition (see chapter 4). In the United States, a man who started to download child pornography after an operation of this kind was recently sentenced to nineteen months of imprisonment! Pedophilia can also be caused by infections of the brain, Parkinson’s, multiple sclerosis, and brain trauma.

  But a neurological cause for pedophilia is rare. Most pedophiles have always been attracted to children, and the cause can be traced to fetal brain development and early development after birth. Just as gender identity and sexual orientation are determined by genetic background and the interaction between a fetus’s sex hormones and its developing brain (see earlier in this chapter), so too pedophilia can apparently be explained by genetic and other factors causing the brain to develop abnormally at an early stage, leading to structural differences. I was once shown a family tree that included three generations of pedophile men. Deviant sexual behavior (like pedophilia) is displayed by a high percentage (18 percent) of first-degree relatives of pedophiles, pointing to a genetic factor. In addition, pedophiles are more likely to have been sexually abused by adults as young children. At the end of 2009, the leader of the Northern Irish party Sinn Féin, Gerry Adams, went public with the painful family secret that his father had abused his own children, while his brother was in turn suspected of having sexually abused his daughter. Whether abuse as a child is a causal factor in the development of pedophilia in adulthood, or whether there’s a genetic factor in such families, still needs to be investigated.

  Daniel Gajdusek (1923–2008), a man of remarkable talent who studied physics, biology, mathematics, and medicine in the United States, thought that abuse as a child could cause pedophilia. He had himself been abused by an uncle as a child. I once had the dubious honor of chairing a lecture by the hypomanic Gajdusek; my colleagues were amused by my vain attempts to keep him in check. Gajdusek had been researching the cause of mass deaths of young women and children from the disease kuru in villages in the interior of New Guinea in 1957. At the time, it was still a Dutch colony, and he was able to find his way there using Dutch ordnance survey maps that he’d stolen from the Leiden endocrinology department headed by Dries Querido. Gajdusek discovered that the deaths were indirectly caused by cannibalism. Long after they had eaten the brains of conquered enemies, the victims were struck down by a slow-acting virus, one of whose symptoms was dementia. The disease turned out to be caused by prions (infectious agents made of protein), just like mad cow disease. In 1996 Gajdusek was awarded the Nobel Prize for Medicine. However, when he returned from New Guinea and other remote locations it wasn’t just with brain tissue for further research; he also brought back fifty-six children, mostly little boys. We always thought this was very odd. He took them into his home and gave them an education but, as an accusation made by a man who had lived with him as a child later revealed, also molested them. He was imprisoned for a year and died in 2008.

  There are all kinds of factors in early development that could influence the risk of developing pedophilia. It would seem logical to study them, but the taboo on this condition stands in the way. Who in our society would dare openly admit to being a pedophile and take part in research into the causes of this disorder?

  In recent years, the first structural differences have been reported between the brains of pedophiles and those of control groups. A study involving magnetic resonance imaging (MRI) showed that the former have less gray matter (neurons) in various areas of the brain, like the hypothalamus, the bed nucleus of the stria terminalis (whose size also differs in transsexuals; see earlier in this chapter), and the amygdala, which plays a role in sex, fear, and aggressive behavior. It moreover emerged that the smaller the amygdala, the more likely an individual was to commit pedophilic crimes. Exposure to emotional and erotic images of adults sparks less activity in the hypothalamus and prefrontal cortex of pedophile men than in control men, which ties in with the fact that pedophiles are less sexually interested in adults. Convicted pedophiles display greater amygdala activity than control men in response to images of children. Functional scans of the brains of homosexual, heterosexual, and pedophile men shown pictures of men, women, girls, and boys moreover show a clear difference between these groups in terms of brain activity. However, we must bear in mind that research into pedophilia focuses solely on a small, selected group of pedophiles. The majority are able to control their urges, don’t commit crimes, and therefore aren’t studied.

  Sexual abuse damages children and is punished, not only for reasons of atonement but also to prevent further abuse. The latter objective poses a problem, though, because how do you change behavior that has been programmed in the brain at an early stage of development? In the past, every conceivable effort has been made to change homosexual men into heterosexuals (see earlier in this chapter), without any success whatsoever. The same applies to pedophiles. Not so long ago, a court in Utrecht heard the case of a sixty-year-old heterosexual church minister charged with pedosexuality. The prosecution called for a sentence of ten months in prison, but after a great deal of deliberation he was eventually given a community sentence. How things have changed.

  There was a time when an obscure mix of arguments bearing on eugenics, punishment, the protection of society, and the repression of homosexuality led to the castration of pedosexuals in the Netherlands. Between 1938 and 1968, at least four hundred sex offenders were “voluntarily” castrated. This practice wasn’t laid down by law. These were offenders detained under a hospital order who were given the choice of life imprisonment or castration. They had to submit a standard letter to the minister of justice, the text of which ran, “May I humbly crave Your Excellency’s permission to be castrated?” Up to 1950, 80 percent of the castrated men were pedosexuals, a situation complicated by the high legal age of sexual consent (sixteen). In Germany, the hypothalami of pedophiles were surgically lesioned in the hope that this would change their sexual orientation. These brain operations were never scientifically documented.

  The incidence of chemical castrations among offenders detained under a hospital order is currently increasing. This involves suppressing the libido with a substance that diminishes the effect of testosterone. It can provide relief at being freed from sexual obsession. However, it’s worrying that some of these individuals are being chemically castrated because the authorities would otherwise deny their applications for leave. These substances certainly aren’t suitable for every sex offender, and the side effects, including the development of breasts, obesity, and osteoporosis, are serious.

  The pedosexual minister from Utrecht can thank his lucky stars that things have changed since the days of formal castration requests. The judge who presided over his case was worried about reoffending, and rightly so. Nevertheless, he thought that the six-week pretrial detention would have a deterrent effect and that the combination of a long conditional sentence and a community order would be more effective than lengthy imprisonment. Whether he was right we’ll never know, because the judicial system has no tradition of researching the effectiveness of its punishments. And the medical world, alas, has no tradition of researching the factors in early development that could cause pedophilia. Doing away with the taboo on such research could shed light on these factors and on the best methods of checking pedophile impulses and stopping people from reoffending. This would prevent a great deal of misery for all concerned.

  The same applies to female pedophiles. The idea that women can’t be guilty of pedosexuality has been found to be a myth. Sexual abuse of children by women is usually perpetrated by mothers on their own offspring. For the most part, the victims a
re girls with an average age of around six. The mothers tend to be poor and uneducated and often have mental health problems like cognitive impairment, psychoses, or addictions.

  An initiative in Canada has shown that it’s possible to tackle this issue by quite simple means. There, pedosexuals are helped by a group of volunteers after their detention. The resulting social network has been shown to cut reoffending rates quite considerably. This is much better than the situation in the Netherlands, where in late 2009, a pedophile was first banned from the city of Eindhoven by its mayor, then prohibited from entering a national park in the province of Utrecht. The man now lives in his car and travels from parking lot to parking lot. That’s asking for trouble. But the Netherlands is now trying out the Canadian initiative. Another way of preventing child abuse might be to issue smart forms of fake child pornography that don’t involve the abuse of real children. Milton Diamond, a renowned sexologist in Hawaii, has found considerable evidence to suggest that this works. However, it will no doubt prove difficult to convince the authorities to consider such an innovative idea.

  PUBLIC RESPONSE TO MY RESEARCH INTO SEX DIFFERENCES IN THE BRAIN

  Angry gays got it all wrong.

  Dutch gay newspaper

  In the 1960s and 1970s the received wisdom was that a child is born as a blank slate and that the development of both its gender identity and sexual orientation are very much determined by social conventions. This notion, one of whose leading proponents was the Philadelphia-based psychologist John Money, had terrible consequences (see the John-Joan-John case earlier in this chapter) but reflected the general thinking at that time that everything could be socially engineered, including whether you felt male or female and were heterosexual or homosexual.

  When I gave my first lectures on sex differences in the brain in the 1970s at the medical faculty in Amsterdam, the broadly held views on the importance of social conditioning weren’t just being trumpeted by Money and his supporters, they were also espoused by the feminist movement. Its adherents believed that all of the differences between the sexes in terms of behavior, occupation, and interest had been forced on women by a male-dominated society. In those early lectures, female students would sit in the front row of the auditorium, demonstratively knitting and crocheting. They made it abundantly clear that the subject I was discussing and my views on the matter were anathema to them. When the light was switched off so that I could show some slides, they protested vociferously, because they couldn’t see their knitting anymore. From then on I turned the lights down and showed slides throughout all classes and lectures. The ladies from the front row sent a delegation to the dean to request a lecturer who would be more sympathetic to women. Apparently none was available, because I never heard any more about it.

  Our description of the first sex differences found in human hypothalami in postmortem brain tissue (Swaab and Fliers, Science 228 [1985]: 1112–15) provoked a hostile response from feminists. At the time there was widespread denial within the feminist movement of possible biological sex differences in the human brain and behavior. Speaking about our findings in an interview with the Dutch magazine HP (January 17, 1987), a woman biologist by the name of Joke’t Hart said, “But if I were to accept that there are differences between the sexes in such fundamental areas as the structure of our brains, I would no longer have a leg to stand on as a feminist.” Whatever the case, I never heard any more of her. Many hundreds of sex differences have subsequently been identified between the male and female brains.

  After we had reported on the first difference found between the brains of homosexual and heterosexual men (later published in Swaab and Hofman, Brain Research 537 [1990]: 141–48; see earlier in this chapter), the unexpected backlash took us by surprise. It all started in December 1988 with an article that appeared in an obscure Dutch publication called Akademie Nieuws. Researchers at institutes directed by the Royal Netherlands Academy of Arts and Sciences (KNAW) had been asked what they were working on, so I’d talked about our brain research into sexual orientation and gender. This was picked up by Hans van Maanen, a reporter for the Dutch daily newspaper Het Parool, who wrote two articles entitled “Gays’ Brains Are Different” and “The Brain Behind Homosexuality,” both of which presented an entirely correct picture. But they unleashed an uproar of unbelievable proportions. What exactly caused this overwhelming and emotional response—which was completely off target—is still a mystery to me. The taboo on a biological explanation for our sexual orientation, which was very marked in an age of boundless belief in social engineering, must have played a role. One group of homosexual men made an almost religious pronouncement to the effect that all men are homosexual, but only some of them opt to come out publicly. They called coming out a political choice. I stated that I couldn’t see how it was political and that the choice of sexual orientation was made for you in the womb; this only fanned the flames. Many hundreds of articles were published in the space of three weeks. COC Netherlands, a gay rights organization, pronounced itself “amazed by the study.” At that time, Rob Tielman, who held the chair of gay studies at the University of Utrecht, was one of my most vocal opponents. He demonized the study by calling it “in extraordinarily poor taste” and claimed, ludicrously, that I should first have asked his permission to carry it out and publish my findings. He later retracted his remarks in an interview in which he said, “My position in the field of gay studies is closest to Swaab’s,” and “I am among those who are inclined to take the biological component very seriously.” But the editor in chief of the Gay Krant, Henk Krol, had meanwhile joined the fray, arguing that “a study of this kind underlines the notion of homosexuality as a disease. In turn, this promotes discrimination against gays.” Questions were asked in Parliament about my study by Peter Lankhorst (Progressive Radical Party). Those questions landed on my desk via the minister of education and science and the president of the KNAW, and my answers went by the same route in reverse. I received threatening telephone calls day and night as well as a card addressed to “the SS Doctor Mengele-Swaab,” which read, “Nazi. Saw your ugly mug on TV. We homosexuals are going to kill you. As an example. Like the leader of Iran did to the Englishman” (fig. 12). At the time I didn’t take it seriously and commented that if their assassination skills were as bad as their written Dutch, I wasn’t in very much danger. Nowadays I think I would be more concerned. I also got a card that read, “Bet you regret not having been able to work under Mengele in Auschwitz!” (fig. 13). Committees scrutinized my research, and I was given bodyguards when I lectured at the Academic Medical Center. The Netherlands Institute for Brain Research became a focus for bomb scares (which I didn’t take seriously either), our children were teased at school, and a demonstration took place one Sunday morning in front of our house, described in inimitable fashion by the (gay) writer Gerard Reve. It even furnished the title for his essay collection A Carefree Sunday Morning (1995). He wrote:

  Only now did it become clear what a serious omission Professor Swaab had been guilty of by failing to ask the homosexual trade union COC permission in advance for his research. The consequences made themselves seen and heard. A large group of motivated individuals appeared in front of Professor’s Swaab’s home in Amstelveen on Sunday morning, chanting loudly, “Dick, cut up your own d—!” A curious choice of words, given that, although Professor Swaab did carry out a study on sexuality, it involved cutting up brains rather than genitals. But this trade union’s adherents don’t have brains, only genitals, so in a way it makes sense.

  It took three weeks for the storm to die down. Then Ayatollah Khomeini pronounced a fatwa on Salman Rushdie after the publication of The Satanic Verses, and suddenly all attention shifted to the British-Indian writer. When the smoke of battle had cleared away and I’d emerged unscathed, the president of the KNAW, David de Wied, gave an interview in the Dutch daily newspaper De Telegraaf in which he backed me up and said that an affair like that should never be allowed to happen again. A pity he hadn’t done s
o a few weeks earlier.

  But I had some nice responses too, like the cartoon by Peter van Straaten (fig. 14) and personal ads in the prominent Dutch weekly magazine Vrij Nederland, like “Nice guy (37, 1.87m, 87kg, fair-haired, blue-eyed) with big hypothalamus is looking for a partner” and “Wanted: BIG suprachiasmatic nucleus, Postbox 654 Wageningen.” Incidentally, it was to be another seventeen years before the Gay Krant revised its take on that period with an article tellingly headed “Angry Gays Got It All Wrong.” Even after all that time, however, Rob Tielman refused to relent. His column in the same issue of the Gay Krant had the sour headline “Swaab Headstrong.”

  FIGURE 12. A postcard I received after publishing the first findings of a difference between the brains of homosexual and heterosexual men, in 1989. Said to be sent on behalf of the COC (gay rights) organization, the text reads, “Nazi. Saw your ugly mug on TV. We homosexuals are going to kill you. As an example. Like the leader of Iran [Khomeini] did to the Englishman. We homosexuals are insulted about our brains.”

  FIGURE 13. Another example of correspondence I received after publishing the first findings of the difference between the brains of homosexual and heterosexual men. The text reads, “Bet you regret not having been able to work under Mengele in Auschwitz!”

  FIGURE 14. Cartoon by Peter van Straaten after the publication of the first findings of the difference between the brains of homosexual and heterosexual men (1989). The caption read, “Wim’s got a big hypothalamus too, eh, Wim?” Original in possession of the author, a present from the Netherlands Institute for Brain Research, NIH.

  Five years after that first brouhaha, the publication of our discovery of a sex-reversed pattern in the brains of transsexuals (Zhou et al., Nature 378 [1995]: 68–70; see fig. 11 in this book) met with an entirely positive response. Transsexuals immediately seized on the article in order to get sex changes registered in birth certificates or passports in countries where that had not previously been possible. It was used to the same end at the European Court of Justice and played a role in the drafting of legislation on the issue in Britain.