Chinese researchers at the Chinese Academy of Sciences recently conducted a study that showed that the brains of gay and bisexual men respond positively to androstadienone, the male pheromone found in male semen and sweat. It also showed that lesbian and bi women respond somewhat similarly to the female pheromone estratetraenol.

Using four separate groups of 24 gay/bi men, straight men, gay/bi women and straight women, participants were shown videos of ambiguous human figures walking forward and then asked to guess whether the human was male or female. They watched these videos while concurrently being exposed to androstadienone or estratetraenol masked with the scent of cloves.

Researchers found:

When exposed to androstadienone, heterosexual women were more likely to suggest that the wire figure was a man—but the pheromone had no effect on heterosexual men (that is, hetero men largely could not detect a male or female presence when presented with the pheromone) Perhaps most importantly, homosexual men also responded to that pheromone, suggesting that gay men innately perceive (and are perhaps affected by) male pheromones.

Straight men, meanwhile, were more likely to perceive the figure as feminine when exposed to estratetraenol. Straight women showed no effect, while lesbian and bisexual women showed a response somewhere in between…

The study’s abstract concludes:

The results provide the first direct evidence that the two human steroids communicate opposite gender information that is differentially effective to the two sex groups based on their sexual orientation. Moreover, they demonstrate that human visual gender perception draws on subconscious chemosensory biological cues, an effect that has been hitherto unsuspected.

Vice.com’s Motherboard notes, “The study is similar in its findings—if not its methods—to one published in Proceedings of the National Academy of Sciences in 2005 that found that the brains of gay men respond in a similar way to straight women when exposed to androstadienone.

The study did not include transgender men or women nor any genderqueer individuals.