no gay genes
There's no such thing as a gay gene.
That's a big finding from a massive genetic study published Thursday in Science, though it doesn't rule out the role of genetics in determining sexuality altogether. Instead, the study has determined that no single gene can determine a person's sexuality, but a combination of genetics and environment surely influence it.
The study drew genetic data from over 477,000 people who've contributed genomes to 23andMe, the UK Biobank, and other databases. Researchers then asked those people whether they'd had sex with a person of the same sex, how they identify on a spectrum of gay to straight, and about sexual fantasies, Scientific American reports. It found that there are five markers on the human genome that have ties to same-sex behavior, but they can only explain up to 25 percent of a person's sexual behavior. That means there's no definitive way to tell a person's sexuality from just their genome — something smaller studies have also found.
Experts pointed out some shortcomings in the study; for example, it mostly studied DNA from older people of European ancestry. The study also "followed convention for genetic analyses" by dropping data from people who don't have the same biological sex and gender, including transgender and intersex people. The study's researchers are working with LGBTQ advocacy groups to find ways best convey these findings, Nature reports. And they all seem to agree on one thing: This kind of research needs more — and more diverse — data.