There's No Gay Gene

The biggest thing upsetting the CRC-PFOX contingent right now is the idea that the Montgomery County schools would say that sexual orientation is "innate." There's no real argument otherwise, everybody knows it's innate, but this just drives them over the edge. They love to repeat the statement "there is no gay gene," over and over again, as if genetic and innate were the same thing.

The Toronto Star had a nice calm story this week about genetics and sexual orientation. How much of it can I include here? Let's see...

Gay men believe their sexual orientation is inextricably bound up with their very being. It is not a choice – let alone the "wrong choice," as religious and political critics have counter-claimed for years.

Many believe they simply were "born that way," and long for proof that their sexual proclivity is biological or genetic, a variation, not a deviation, of human nature. And how can an innate instinct be the subject of discrimination?

But just as many gay men don't want to know. It's a predisposition, they say, what does it matter what kind? If science delves into the cause, then bet on it, someone will set about finding a "cure." More to the point, they argue, determining the why of homosexuality won't end prejudice.

"The emphasis on finding a biological cause is much more widespread among activists in the U.S. than in Canada," says political scientist David Rayside, director of the University of Toronto's Sexual Diversity Centre.

"Most people here don't care or think the fight for gay rights shouldn't hinge on finding a cause." Hunting the gay gene

Interesting to contrast the US and Canada. I think we'll hear more about that in the comments.

I have talked to people who think this is a huge deal. I personally don't think it matters that much -- for instance, I think it is proper to respect a person's religion, even though that is obviously a choice and not something that is innate. It doesn't mean I should discriminate against them on the basis of their religion. But sexual orientation is different, it's not something a person chooses, it's clearly got a biological aspect to it, and that would, I think, entirely justify rejection of variation in sexual orientation as a dimension for judging people morally.

Theories have been floated for more than a century on what triggers homosexuality. Nurture – a psychologically troubled relationship between parents and child – held top billing until the start of the 1990s, when the tide shifted toward nature.

Two American scientists set the research and the debate in motion.

In 1991, Simon LeVay, a neurobiologist at the Salk Institute of Biological Studies in California, examined the brains of 41 individuals; 19 gay men who died of AIDS, 16 heterosexuals of drugs-related AIDS and six women, of whom one had died of the disease.

Already aware that certain areas of the brain are bigger in men than in women, LeVay checked to see if there was a size variation with the gay men.

To his surprise, he found that one grouping of cells associated with sexual activity was twice as large in straight men as it was in both gays and women.

LeVay emphasized that his work didn't show "how or when sexual orientation is determined, only that it is an aspect of human nature that can be studied by biologists." But the media ran with it, playing down widespread criticism that he hadn't factored in the effect of AIDS on the brain.

Yeah man, that's just a start. One study with a few dozen subjects is not going to answer this question. For one thing, this is pure correlation, and you know what they say.

The story then talks about a study by Dean Hamer, who found some places on the chromosome that seemed to correlate with sexual orientation. The newspapers all went on about a "gay gene" being found.

Wrongly so, said the genetics community. The coverage was inflated, simplistic and misleading. No "gay gene" had been found, nor ever would be. Why? Because behavioural genetics is much more complex than "Mendelian" genetics. In other words, traits such as eye colour are 100 per cent inheritable but the genetic contribution to various behaviours, aggression, shyness, extroversion and so on, is considerably less, below 50 per cent.

Ruth Hubbard, Harvard emeritus professor of biology and biochemistry and author of Exploding the Gene Myth, has said that searching for a gay gene "is not even a worthwhile pursuit.

"I don't think there is any single gene that governs any complex human behaviour. There are genetic components in everything we do, and it is foolish to say genes are not involved, but I don't think they are decisive."

I saw the CRC's resident MD give a talk once where she showed data from a twin study that found that when a twin was gay he was ten times more likely than average to have a gay brother. She argued that the data actually showed that sexual orientation is not genetic, because if it was, they would both be gay a hundred percent of the time. Just goes to show you, people see things differently.

Ooh, there is something deliciously ironic in this next sentence:

By the end of the '90s, interest in the hunt for a gay gene had waned. Why, skeptics asked, would there be one when it plays no role in the evolutionary scheme of things?

This next guy has been at the center of a lot of the recent discussion; his name was first mentioned by a conservative writer as supporting their view that orientation is a choice, but he then explained: "The evidence we have at present strongly supports the proposition that there are hereditary factors in male homosexuality."

Since then, the scientific consensus is that sexual proclivity is influenced, but not hardwired, by DNA. Geneticist Francis Collins, head of the international Human Genome Project, has written that "whatever genes are involved represent predispositions, not predeterminations."

But the debate hasn't entirely gone away, or, indeed, all of the research. Next year at Northwestern University, 1,000 pairs of gay brothers will be studied to see if Hamer's X-chromosome findings finally can be reproduced. (Driven by AIDS, as well, critics would argue, by cultural bias, science has focused overwhelmingly on men, not gay women.) U of T's Rayside is leery about yet another study, concerned at society's increasing temptation to interpret all kinds of human behaviours in biological, particularly genetic, terms.

"These scientists think they're doing good, but they don't realize there's a political component to their work. It contributes to the trend toward genetic selection."

I suppose there's always the threat that knowledge will be used for foul purpose, but I don't see that as a good reason to remain ignorant. Who knows, maybe they'll find the gene that causes people to use knowledge for foul purpose, and use that knowledge to make people nice.