Humans have a nose for gender

May 01, 2014
nose
Image: Wikipedia.

The human body produces chemical cues that communicate gender to members of the opposite sex, according to researchers who report their findings in the Cell Press journal Current Biology on May 1. 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. The effect, which occurs completely without awareness, depends on both our biological sex and our sexual orientations.

"Our findings argue for the existence of human sex pheromones," says Wen Zhou of the Chinese Academy of Sciences. "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."

Earlier studies showed that androstadienone, found in male semen and armpits, can promote positive mood in as opposed to males. Estratetraenol, first identified in female urine, has similar effects on males. But it wasn't clear whether those chemicals were truly acting as sexual cues.

In the new study, Zhou and her colleagues asked males and females, both heterosexual and homosexual, 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 , plus the pelvis, thorax, and head. The task was to decide whether those digitally morphed gaits were more masculine or feminine.

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Each participant repetitively viewed seven PLWs, one at a time in random order, whose genders ranged in seven equal steps from feminine (0.45 SD) to masculine (0.45 SD), with 0 marking the approximate gender-neutral point individually adjusted in the absence of olfactory stimuli. Participants made a forced choice judgment on whether each PLW was a male or female walker. The movie shows five walking cycles. Credit: Current Biology, Zhou et al.

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 heterosexual females, but not males, toward perceiving walkers as more masculine. By contrast, the researchers report, smelling estratetraenol systematically biased heterosexual males, but not females, toward perceiving walkers as more feminine.

Interestingly, the researchers found that homosexual males responded to gender pheromones more like heterosexual females did. Bisexual or homosexual female responses to the same scents fell somewhere in between those of heterosexual and females.

"When the visual gender cues were extremely ambiguous, smelling androstadienone versus estratetraenol produced about an eight percent change in gender perception," Zhou says, a statistically very significant effect.

"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," the researchers write. "Moreover, they demonstrate that human visual perception draws on subconscious chemosensory biological cues, an effect that has been hitherto unsuspected."

Explore further: Study brings greater clarity to sex roles

More information: Current Biology, Zhou et al.: "Chemosensory communication of gender through two human steroids in a sexually dimorphic manner." http://www.cell.com/current-biology/abstract/S0960-9822(14)00327-3

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User comments : 5

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Z99
5 / 5 (2) May 01, 2014
No mention on sample size? Shoddy journalism - even the WSJ does a better job.
freethinking
1 / 5 (2) May 01, 2014
Wait, I've been told by progressives that there are more than just two genders. The person who wrote this article and the people who did it should go to Obama's Re-education camps.
Uncle Ira
3.7 / 5 (3) May 01, 2014
This one is a good one for the JVK-Skippy and his stinky love potions what he sells.
JVK
1 / 5 (4) May 01, 2014
Journal article excerpt: "...human visual gender perception draws on subconscious chemosensory biological cues, an effect that has been hitherto unsuspected."

Simon LeVay's comment on my model: "This model is attractive in that it solves the "binding problem" of sexual attraction. By that I mean the problem of why all the different features of men or women (visual appearance and feel of face, body, and genitals; voice quality, smell; personality and behavior, etc.) attract people as a more or less coherent package representing one sex, rather than as an arbitrary collage of male and female characteristics. If all these characteristics come to be attractive because they were experienced in association with a male- or female-specific pheromone, then they will naturally go together even in the absence of complex genetically coded instructions."
JVK
1 / 5 (4) May 01, 2014
The Scent of Eros: Mysteries of Odor in Human Sexuality
http://www.amazon...ghn+kohl

See page 109 for the first evidence of the effect that Zhou et al claim has been hirtherto unsuspected.

Then see the author's copy of my award-winning review:
The Mind's Eyes: Human pheromones, neuroscience, and male sexual preferences
http://www.sexarc...kohl.htm

"Olfactory/pheromonal conditioning elicits neuroendocrine effects accompanied by unconscious affects on the development of sexual preferences. Integrating these unconscious affects extends to humans a developmental model of behavior that includes the development of male sexual preferences for other males."

See also this award-winning review: Human pheromones: integrating neuroendocrinology
and ethology http://www.nel.ed...view.htm