If you’re gay and you have an older brother, you can now officially blame it on him next time your parents bring up that awkward topic during Christmas dinner. And you’ll have scientific research to back it up.

Researchers published a study in the journal,PNAS this week that concludes a possible biological explanation to why some men are gay. Although previous research has found a pattern of men with older brothers to be gay, this study links the phenomenon to something that takes place in the womb.

We know what you’re thinking. No, it’s not if your mother listened to Cher while she was pregnant.

The theory has to do with the Y chromosome, which is unique to cis men and a factor in male brain development. Since cis women do not possess this chromosome, researchers think it’s possible that when a woman becomes pregnant with her first boy, the Y-linked protein gets into her bloodstream and the body recognizes it as a foreign substance. In response, her immune system creates antibodies.

But when she gets pregnant with another boy, this antibody can cross the placental barrier and enter the brain of the male fetus. According to Anthony Bogaert, Canadian psychologist, professor, and author of the study, this could alter the brain’s functions, affecting how men develop their sense of attraction.

Previous research found that the more older brothers a boy had, the more likely it was he would be gay. A2006 study found that with each older brother, the chance a man will be gay increases by a third. This was found across multiple cultures, even if the brothers were raised separately. But no possible explanation was found until now.

If this biological explanation turns out to be true, it’s not only a significant scientific finding. It also means Lady Gaga’s “Born This Way” is more than just a convenient philosophy, it’s scientific fact.

Help make sure LGBTQ+ stories are being told...

We can't rely on mainstream media to tell our stories. That's why we don't lock our articles behind a paywall. Will you support our mission with a contribution today?

Once Monthly Annually

Cancel anytime · Proudly LGBTQ+ owned and operated