London, May 2 (IANS): And you thought you can tell a person's gender based on how he or she looks?
Actually, you make subconscious judgments based on how a person smells.
You are not aware of this at the conscious level but your nose is busy doing its job - sniffing out that feminine smell from secretions her body is oozing near you in marketplace, office or mall!
According to researchers, the human body produces chemical cues that communicate gender to members of the opposite sex.
Whiffs of the active steroid ingredients (androstadienone in males and estratetraenol in females) influence our perceptions of movement as being either more masculine or more feminine.
"Our findings argue for the existence of human sex pheromones. They show that the nose can sniff out gender from body secretions even when we do not think we smell anything on the conscious level,” explained Wen Zhou of the Chinese Academy of Sciences.
Earlier studies have shown that androstadienone, found in male semen and armpits, can promote positive mood in females as opposed to males.
Estratetraenol, first identified in female urine, has similar effects on males.
But it was not clear yet whether those chemicals were truly acting as sexual cues.
In the new study, Zhou and her colleagues asked males and females to watch what are known as point-light walkers (PLWs) move in place on a screen.
PLWs consist of 15 dots representing the 12 major joints in the human body, plus the pelvis, thorax and head.
The task was to decide whether those digitally morphed gaits were more masculine or feminine.
Individuals completed that task over a series of days while being exposed to androstadienone, estratetraenol, or a control solution, all of which smelled like cloves.
The results revealed that smelling androstadienone systematically biased females, but not males, toward perceiving walkers as more masculine.
By contrast, smelling estratetraenol systematically biased males, but not females, toward perceiving walkers as more feminine.
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, said the study that appeared in the Cell Press journal Current Biology.