The Smell of Sex: How Humans Detect Pheromones in Potential Partners

There's nothing like a whiff of pheromones to get the chemical signals all riled up.  Of course, we might not know it, but this is how we subconsciously identify the opposite sex. A recent study examines how this chemical cocktail helps us determine different genders. 

"Our findings argue for the existence of human sex pheromones," said lead researcher Wen Zhou of the Chinese Academy of Sciences, via Live Science. "They show that the nose can sniff out gender from body secretions even when we don't think we smell anything on the conscious level."

For the study, researchers had gay and straight male and female participants watch point-like walkers (PLWs) move in place on a screen. PLWs consist of 15 dots that represent the 12 major joints in the body, along with the thorax, pelvis and the head. Participants were then asked to determine whether the digitally manipulated walks were masculine or feminine.

Throughout the span of the study, the participants were unknowingly exposed to androstadienone, estratetraenol, or a control solution, all of which smelled like cloves.

Findings showed that straight females exposed to androstadienone were more likely to perceive the walkers as masculine. However, the smell of estratetraenol influenced straight males to perceive the walkers as feminine.

Homosexual males responded to gender pheromones more like heterosexual women. Yet bisexual or homosexual females participants had mixed views regarding the walkers.

"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," study authors noted. "Moreover, they demonstrate that human visual gender perception draws on subconscious chemosensory biological cues, an effect that has been hitherto unsuspected."

More information regarding the findings can be seen via the journal Current Biology.