Finding a mate is one of the basic instincts of all living beings, and in most of the animal and insect world, it’s all done by smell. Sniffing out gender is something that animals are built to do, both with the appropriate scent-releasing structures to perfume the air with sex pheromones, and the most sensitive odor-detecting organs on the planet.
Now scientists report in the journal Current Biology that people may have that ability as well, even if we aren’t always aware of it. Humans don’t have the same sophisticated olfactory organs as some of our animal counterparts, and while men and women do exude different scents, it’s been harder to confirm that people can pick up on these odors, or that they were working as sex pheromones to attract two people to each other.
In the latest study on the subject, researchers in China and at the University of Minnesota conducted a small study in which both men and women of different sexual orientation were exposed to male, female or neutral scents without their knowledge on three consecutive days while they viewed a series of computer dots representing a person walking.
Heterosexual men thought the dots showed a more feminine gait when they were exposed to the female hormone estratetraenol. There was a similar effect among heterosexual women, who were biased to see the dots showing a more masculine gait when they smelled the male hormone androstadienone. Gay men responded more like the women to the two hormones, while bisexual or homosexual women showed more varied responses, between those of heterosexual men and women.
“The study shows that people subconsciously extract gender information from chemosensory cues [that depend] on their gender and sexual orientation,” says Wen Zhou, the study’s lead author from the Chinese Academy of Sciences in Beijing, in an email discussion about the findings.
Zhou isn’t quite ready to say that estratetraenol and androstadienone, which are steroid products of estrogen and testosterone, respectively, work as sex pheromones between men and women by acting as sexual stimulants, since the group did not test how smelling varying amounts of the agents affected people’s sensitivities toward gender.
But the findings provide the first hint that gender may have specific scents, and that the human nose and pick up on them. The study also suggests that the human nose may be relaying information about much more than smells that the brain processes on a conscious level. Recent studies, in fact, have confirmed that our olfactory sense is capable of picking up one trillion smells, and that we can pick up whiffs of illness when somebody’s immune system is activated. There’s even evidence that the human nose can smell age – an evolutionarily helpful skill that distinguished younger, more fertile mates from older ones. We are only beginning to understand what the nose knows, and we imagine ensuing research will continue to surprise and baffle us all.