Love & Sex

Science Finds a Gene That Influences Whether You’re Gay or Straight

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Science Finds a Gene That Influences Whether You're Gay or Straight

DNA isn’t the only factor, but it’s a factor.

By Rachel Sugar

A new study finds fresh evidence that your sexual orientation is written in your genes — or at least, it’s drafted there. DNA may not be the only factor that determines sexuality — or even the main factor that determines sexuality — but researchers from Northwestern have new data suggesting that at the very least, it’s a factor. 

Scientists tested the DNA of 400 gay men, and found that at least two chromosomes have genes that affect whether a man is straight or gay. There’s still more research to be done — researchers now know, for example, that X chromosome Xq28 and chromosome 8 are both in play, but the specific mechanisms aren’t clear yet.

What is clear, though, the Guardian reports, is that genes matter: according to lead researcher Michael Bailey, the study definitively showed that “there are genes involved in male sexual orientation.” But while a controversial 1993 study showing similar results set off a firestorm of panic — if sexuality was genetic, then would parents want prenatal orientation testing? — Bailey and his team say that genetics aren’t the whole story. DNA is “not completely determinative,” Bailey explains, citing “other environmental factors” as being pivotal pieces of the sexuality puzzle. If it were completely genetic, then all gay men would have the genes and identical twins would necessarily share an orientation. Neither is the case. Not all gay men inherited the same Xq28 regions, and most often, a gay twin has a straight brother. Sexuality, we knew and science confirms, is complicated. 

But if genes aren’t everything, then what are they, exactly? Bailey’s colleague, Alan Sanders, puts it best: “Whatever gene contributes to sexual orientation, you can think of it as much as contributing to heterosexuality as much as you can think of it contributing to homosexuality. It contributes to a variation in the trait.” It’s not a “gay gene.” It’s a “one-of-many-factors-contributing-to-orientation” gene. Which shouldn’t surprise us. All human psychological traits have at least some genetic component, King’s College London psychologist Qazi Rahman points out. Sexual orientation is just like everything else. But that doesn’t mean it’s not an avenue for more research. 

Image via Inferkiss