Genes and sexual orientation: Tale of two activists

Over at Americans for Truth About Homosexuality (AFTAH), Pete LaBarbera alerted his readers that he was on WGN last night in connection with a story about “gay genes.” He noted in a mass email yesterday (did anyone see it?):

Americans For Truth will be featured tonight in a story on the cable super-station WGN-TV, based in Chicago, concerning the latest academic pursuit of the “gay gene.” It will air between 9:00 and 10:00 Central Time on WGN which reaches across the country. You can learn more about the (liberal biased) Northwestern U. “genetic homosexuality” study at www.gaybros.com. As you know, pro-homosexual advocates are seeking to prove that homosexuality is genetic — with the hope of then declaring the issue outside the bounds of moral debate.

While this is not a strong denouncement of the project, it appears that AFTAH believes the research led by Alan Sanders is biased from the start. LaBarbera is right that some activists would like to prove a genetic source of homosexuality (case in point below). However, what if there are genetic components to sexual orientation? Is there any way to discuss or research these factors without being considered “liberal” and/or “biased?” Isn’t a blanket dismissal of pre-natal factors just as biased?

On the other hand, as if to prove LaBarbera’s point, enter Wayne Besen’s new videos from Dean Hamer and Jack Drescher.  To Dean Hamer, Besen poses the question, “Is homosexuality inborn?” Hamer replies that “there is more and more evidence that sexual orientation has a strong biological component.” Hamer then points to two “population based studies of twins.” One is Kendler’s study in the US and the other is Bailey and Martin’s study in Australia. Hamer says these studies “have shown that genes are the single most important factor in whether a person is gay or straight or somewhere in between.” He said the studies have been replicated and are convincing. I will save for another post a detailed response to those statements, but for now I will say that I do not agree with Dr. Hamer’s characterizations. For instance, in the Australian study, the actual concordance of homosexuality among male identical twins was only 11%. Kenneth Kendler and colleagues in 2000 found a higher concordance (31.6% combining males and females), but did not designate genetics as being a determining factor. About his study of twins, Kenneth Kendler told the BBC,

By no means is sexual orientation genetically determined but clearly genes are playing some role by interacting with a range of environmental factors.

Dr. Drescher’s video provides a more nuanced and I think accurate reading of research. About those who say they know what causes sexual orientation, Dr. Drescher says, “The truth of the matter is, we don’t know, nobody knows, and anybody who says that they know is lying to you.” Drescher also presents a reasonable view of the role of sexual abuse saying that for individual people, such abuse could play a role but as a general rule, believing abuse to be at root is an unfounded stereotype.

Now, coming full circle back to the website LaBarbera noted in his email – gaybros.com, we find a nuanced and I believe accurate view that cuts between activists Besen and LaBarbera. Here are a couple of excerpts:

At the present time, there is no uniformly accepted theory of why some men and some women develop a sexual orientation that is more or less exclusively focused on members of their own sex.

and

Most contemporary researchers believe that sexual orientation – the general disposition of people toward homosexuality, bisexuality, or heterosexuality – is the result of both biological factors and psychological experiences. Most researchers do not believe that sexual orientation is the result of nature (biology, including genetics) alone or nurture (environment) alone. What researchers want to know is how specific factors in biology and psychology interact to guide sexual development. These researchers therefore look for biological and psychological differences between homosexual and heterosexual people, both men and women.

Then after listing the many studies which find biological factors correlated with sexual orientation (e.g., finger length ratio differences, brain differences, etc.), the website says this:

These studies are designed to show a correlation between a trait and sexual orientation. This is not the same as showing that a trait causes sexual orientation. What is not yet known is whether these traits and sexual orientation have a common origin in genetics or other biological influences on development, though these hypotheses are being pursued. In any case, these lines of research are suggestive rather than definitive. Among other factors, it is these and other uncertainties that prompt continued research.

These statements sound anything but biased to me. All concerned would do well to heed them. Working hard to spin what is known may play well to activists but saying homosexuality is or isn’t all “genetic” or “inborn” or “environmental” does not well represent what is known. We need to follow the research where it leads and hold our theories loosely.