Are Gay Men Born That Way?
By Christine Gorman;J. Madeleine Nash/Los Angeles Monday, Sep. 09, 1991 *
Gay men often claim that even as children they knew they were somehow "different" from other boys. Many say that sense even preceded puberty. And yet, though researchers have tried for decades to identify a biological basis for homosexuality -- which seems to be present in all human societies -- they have mostly come up dry. Tantalizing clues have surfaced: gays are more likely to be left-handed, for instance. But in the end, there has been little proof that biology is sexual destiny.
Now new research offers evidence that there may indeed be a physiological basis for sexual orientation. In a study of 41 brains taken from people who died before age 60, Simon LeVay, a biologist at San Diego's Salk Institute for Biological Studies, found that one tiny region in the brain of homosexual men was more like that in women than that in heterosexual men. "Sexuality is an important part of who we are," notes LeVay, who is gay. "And now we have a specific part of the brain to look at and to study."
That specific part is found at the front of the hypothalamus in an area of the brain that is known to help regulate male sexual behavior. Within this site, LeVay looked at four different groupings of cells, technically referred to as the interstitial nuclei of the anterior hypothalamus, or INAH for short. Other researchers had already reported that INAH 2 and 3 were larger in men than in women. LeVay hypothesized that one or both of them might vary with sexual orientation as well.
Routine autopsies provided the tissue LeVay needed. All 19 homosexual men had died of AIDS. So had six of the 16 presumed heterosexual men and one of the six women. Although LeVay hoped to include lesbians in his study, he was unable to obtain brains from women identified as such. After careful examination of the brain samples, he found that the INAH-3 areas of most of the women and homosexual men were about the same size. In straight men this region was on average twice as large -- or about the size of a grain of sand.
In the past, much research on sexual orientation has focused on the role of interpersonal relationships in early childhood. Psychological literature is replete with material suggesting that male homosexuality is triggered by relationships with an overly protective mother or with a distant, even hostile father. "Here is a whole other way of looking at the question," says LeVay. "These children may already be determined to become homosexual or heterosexual. The development plan that is laid out for them may be what causes them to develop certain troubled relationships with their parents."
LeVay's findings are certain to trigger a good deal of controversy. Many technical aspects of the study are subject to question, as the author concedes. He cannot be certain, for instance, that all the heterosexual men in the control group were heterosexual. And since the AIDS virus attacks the brain, the size difference could be an artifact of the disease. It is also possible that the difference actually has nothing to do with sexual orientation or that it is the result rather than the cause of homosexuality.