The hunt for a “gay gene” has been controversial for a while, both in politics and in entertainment. That controversy is likely about to flare up again with new reports of genetic factors in sexuality being uncovered.
But the headlines are obscuring what’s really in the science, which is much more subtle and complex.
- The controversy stems from two key problems: The hunt for genetic factors in homosexuality has two problems. One, there is a contingent of people, ranging from well-meaning to bigoted, who want to argue it’s psychological, not biological. If sexuality is biologically encoded in who we are, that has impact in realms well beyond the medical and scientific. Two, LGBT advocates fairly point out that there’s no hunt for the “straight gene.” It’s fair to ask why being gay is lumped into the same category in many scientific minds as, say, cystic fibrosis. The gay community has a long history of being mistreated by doctors seeking to “cure” them, and that’s at the back of the minds of anybody familiar with medical history, gay or straight. The irony, though, is that finding genetic factors for sexuality is turning up that the topic is far more nuanced and complicated than anybody thought.
- Most of this dates to the mid-’90s, when variations on two chromosome were found to potentially affect sexuality: Unsurprisingly, variations on chromosome 23, the X chromosome, were found to potentially have an impact. But also in 1995, chromosome 8 was found to have some impact. This has been confirmed by peer review, but it’s not the whole story.
- Sexuality appears to be strung across a whole range of genes: The new research is about gene expression and sexuality, and sequenced the genomes of 1077 men who identified as gay and 1231 men who identified as straight. What it found was that there were two more very slight genetic differences, on chromosome 13, which affects the hypothalamus, which is involved in the autonomic nervous system and chromosome 14, which affects the thyroid. And it seems very likely there will be more. It’s worth remembering we are talking about tiny, tiny differences here, and there’s no one gene that shifts somebody to a point on the sexuality spectrum. Instead, it’s looking more and more like it’s a number of genetic changes that add up over gestation, and likely beyond, that determine where somebody falls.
- In other words, there’s no gay gene or even any reliable way to figure out someone’s sexuality from genetics: Even the scientists running the study argue there are likely dozens of factors, some external, some internal that lead to a person’s sexuality. For example, social pressures lead to a phenomenon, particularly intense among men, called bi erasure. Men have to “pick a side,” as it were, which may influence the research. After all, for all we know, some of the gay men and straight men in the study may be closer to bi, and are simply choosing a socially acceptable identity. And then there’s the bigger problem…
- What about women? Simply put, the idea of there being “lesbian genes” remains largely untested. All of this research applies to men. What shifts men across the sexual spectrum, genetically or otherwise, may be the same for women, it may overlap, or it may be completely different. It’s a giant flaw in the research nobody’s quite sure how to fix.
The takeaway? Our sexuality may be driven, in part, by individual genes. But it’s not the whole picture, and social pressures, the environment we grow up in, and a host of other factors may play into how we do, and don’t, express our sexuality publicly. Genetics are the instrument, but the song played on that instrument is, by and large, still mysterious.
