the dud studs, but it suggests that there are definite biological reasons ‘that brain structures involved in sensing or perceiving potential mates may be different in homosexual and non-sexual rams’. The dud rams it seems have a different brain from the heterosexual rams.
But what about humans? Empirical evidence suggests that human sexual orientation is determined by exposure to testosterone during the third month of pregnancy, but is there any physical evidence? Again it is the hypothalamus that most interests scientists because the human hypothalamus, like the rat’s, controls sexual behaviour, and, just as in rats, distinct differences have been found in the male and female human hypothalamus. There is an area in the hypothalamus called the sexually dimorphic nucleus of the preoptic area, and researchers have demonstrated that this area is always larger in male brains than in female brains; in rats it is between five and seven times larger, while in humans it appears to be two or three times larger.45
This same area was investigated in homosexual men. Simon LeVay, in a controversial discovery, announced that the sexually dimorphic nucleus of the preoptic area was twice as large in heterosexual men as in homosexual men, which meant, simply, that gay men presented a female brain structure.46 LeVay’s announcement made headlines all over the world and, not surprisingly, excited controversy. If he was correct, the gay lobby could no longer be confident that homosexuality was a ‘social construct’. It looked more and more like a biological phenomenon, so it was with some relief that the gay lobby announced that LeVay’s findings had to be wrong because the brains he had dissected had all come from gay men who had died of AIDS, and AIDS can cause changes in brain structure. That criticism lost its force after LeVay investigated the brains of homosexuals who had not died of AIDS, and once again discovered that they presented a typical female pattern.47
LeVay’s findings are no longer controversial. Indeed, other researchers are discovering still more differences between the structures of the homosexual and heterosexual brains – the suprachiasmatic nucleus, also in the hypothalamus, seems to be larger in women and gays than in straight men,48 while the anterior commissure, a kind of telephone exchange that joins the right and left temporal lobes of the brain and is significantly larger in women than in men, has now, it should come as no surprise, proved larger in gays too.49
The probability that sexual orientation is determined in the womb looks more and more likely, except to those blinded by sexual politics. Yet more proof of the power of foetal hormones to affect adult behaviour comes from studying children who, because of a genetic abnormality, were exposed to abnormal levels of sex hormones while in the womb. Certain girls have an abnormality in their adrenal gland that leads to an overproduction of androgens or male hormones. The condition is called congenital adrenal hyperplasia, or CAH, and CAH girls are born with internal female sex organs but partly masculinized external genitals. Surgery can usually correct the genital abnormality and drugs can control the build-up of male hormone, but many studies have shown that these girls still behave quite differently from girls who were not subjected to high foetal levels of androgens.50 The androgen-affected girls are masculine in their general behaviour: they are more aggressive than other girls, more ‘tomboyish’, preferring male toys (guns and model trucks) to dolls, and are more interested in competitive sports. Even at a very young age children look to their own sex for playmates, but the androgen-affected girls instinctively seek to play with boys. In adulthood they are far less interested in men, marriage and sex than other women, 48% of them confess to having homosexual fantasies,51 and 44% are actively lesbian.52
These studies provide further evidence of the power of foetal hormones to determine sexual behaviour and orientation, though some critics dismiss the CAH studies on the grounds that the affected girls, because they were born with male genitalia, were raised by their parents as though they were boys. This reinforces the postmodern belief that sexual orientation is constructed by societal pressure, though in fact there is no evidence that the parents of androgen-affected girls do compromise their children’s sexual identities by treating them differently. The girls do not behave like boys because their parents treat them as boys, but because their brains were set into the male pattern in the foetus. More evidence of such hormonal influence is provided by a few cases where pregnant mothers were exposed to atypical hormones during medical treatment, and once again the results are clear. The more testosterone a foetus receives, the more male the behaviour of the subsequent child.53
If this is true then we might expect to see a reverse manifestion – the less testosterone a foetus receives, the more female the behaviour – and such a correlation does exist: 70% of male homosexuals displayed a preference for girl-type play as children.54 The first such signs usually show when the child is a toddler. He will sometimes assert that he is a girl, perhaps favour cross-dressing, and he will frequently prefer the company of girls as playmates to that of boys. Parents frequently try to stop this kind of behaviour and sometimes take such children for psychiatric treatment, and it is from that caseload that most studies of homosexual childhood originate.55 ‘The differences in childhood history between homosexual and heterosexual groups are striking’, but they are also precisely what one might expect if the cause is biological and not societal.
Not only behaviour but also abilities are affected by hormones. Girls who are exposed to male hormones in the womb have better spatial ability than normal girls (spatial ability helps us to park a car in a narrow space). The significance of this finding is that differences in spatial ability are one of the largest measures of difference between the sexes. Boys and men, for example, are much better at judging size and distance than girls and women, and spatial ability translates into all sorts of practical differences. Sense of direction and hand-eye co-ordination are consistently superior in men, which is why a male darts team is consistently better than a female one.
There have been two studies of hand-eye co-ordination that measured how well the subjects could throw a missile and hit a target. The studies discovered that the homosexual’s ability to throw accurately was much poorer than the ability of heterosexual men; in fact homosexual target throwing was like a woman’s.56 Another study, related to neither ability nor behaviour, has shown that homosexuals possess fingerprints of the female pattern.57 Hall and Kimura conclude that these findings are consistent with a biological contribution to sexual orientation and indicate that such an influence may occur early in prenatal life – exactly what our other researches have discovered. An even more recent study found that lesbian women literally hear like men. There is a sex difference in the structure of the inner ear that is under the control of foetal testosterone. Lesbians have the male type of inner ear structure.58
The evidence for the foetal origin of human sexual orientation is indirect, simply because we cannot test the hypothesis by direct experimentation, but it is still overwhelming. Our sexual nature is laid down in the womb. It is possible that there might be some genetic predisposition to homosexuality or to heterosexuality, but it is not necessary to postulate a genetic cause when the hormonal evidence is so compelling. Society does not construct homosexuality, nature does, and it does so at a time when the homosexual has no choice in the matter. Being gay, then, is not a perversion of biology, it is not a conscious lifestyle choice and it is not a disease. It is a natural variation of human sexuality.
We are still a long way from understanding the full causes of homosexuality, though no serious scientist would any longer deny that those causes lie in biology. When it comes to sexual orientation, as with other inherited traits, it is the cumulative effect of evidence from different areas that proves the case. Single studies have their flaws, but the sheer number of studies all indicating the same thing makes it hard to understand why there is still any argument about the proposition that sexual orientation is an inborn biological trait.
At this point the critics will say: ‘Yes that’s right and it is all too complex to unravel. It is impossible to separate the cultural and biological influences.’ They usually then add, ‘And anyway cultural influences are so much stronger, so why bother with those little bits of biology?’ But there is a stability in the
