More on 'the biology of gayness'

Story and interview here.

One way to distinguish the effects of nature from nurture would be to look at brain regions believed by neuro-anatomists to be fully formed at birth and impervious to subsequent environmental effects, both physical and psychological. Focusing on such brain regions, a research team at the Karolinska Institute in Stockholm, Sweden, headed by neuroscientist Ivanka Savic, obtained MRIs for 90 adult volunteers -- 25 straight men, 25 straight women, 20 gay men and 20 lesbians. Using the latest quantitative techniques for assessing cerebral symmetry and functional connections between various areas of brain, Savic was able to demonstrate highly statistically significant differences between straight and gay brains. Gay and lesbian brains more closely resembled the brains of straight volunteers of the opposite sex than the brains of heterosexual members of the same sex.

In their study, reported in the June 16, 2008, issue of the Proceedings of the National Academy of Sciences, Savic said, "This is the most robust measure so far of cerebral differences between homosexual and heterosexual subjects." Although Savic admits that her study cannot distinguish between genetic or prenatal intrauterine environmental changes, such as relative differences in sex hormone levels, her studies do suggest that our sexual preferences are, at least in large part, determined by the time of birth. . . .

Do you think these studies can help counter fundamentalist arguments that homosexuality is evil?

Accepting sexual preference as an innate characteristic is an essential first step. But this sidesteps the more deep-seated gut sense that homosexuality isn't natural and goes against the laws of nature. This argument can be partially defused by recognizing how ubiquitous homosexual behavior is in the animal kingdom -- starting with the lowliest fruit fly. I'm sure you're aware that there is a single gene, which, in the fruit fly, can turn on and off homosexual behavior.

But in the end, I suspect that real acceptance will only come about when we have a much more comprehensive view of how the mind works, including how we make conscious choices versus how much of our apparent willfulness arises out of involuntary biological mechanisms.