Picture your average nerdish zoologist, bespectacled and surrounded by animals. Now let’s add the slightest hint of aftershave or deodorant: suddenly this zoologist is a stud, so irresistible that he must fight off members of the opposite sex with a baton.
Welcome to the world of advertising, where smell is the ultimate aphrodisiac.
I can tell you right now, those billboards are wrong. I could bathe in a swimming pool of Old Spice and still have zero success with the ladies.
But that doesn’t mean smell doesn’t matter. In a previous blog, I described how body odour can tell us about a partner’s immune system, and it doesn’t stop there. Let’s talk about pheromones.
Your bodies are actively producing pheromones right now
You may have noticed that teenagers don’t smell very nice. There’s a good reason for this: at puberty our apocrine glands (found mainly in the armpits, nipples, and groin) started churning out steroids.
At first, these secretions don’t smell like anything, but coccal and coryeform bacteria helpfully transform them into androstenone and androstenol, which stink to high heaven. Because women have more coccal bacteria, and men more cornyneform bacteria, each sex has a distinctive body odour.
But humans aren’t the only ones who produce androstenone and androstenol. You’ll also find them in the saliva of wild boars, who consider the odour so enticing that females in heat will immediately assume the mating stance. But surely humans are not shallow as all that..?
Androstenol makes you like people more
A pioneering 1978 study into human pheromones asked undergraduate students to rate the attractiveness of photographs while wearing a surgical mask. No, the mask was not merely for aesthetic purposes – in half the cases, it was soaked in androstenol.
The results were strikingly clear. While inhaling a whiff of androstenol, students were more likely to find the photographed women more attractive, and to find both men and women “warmer” and “more friendly.”
So, according to this study, pheromones can influence our judgement of others. But you’ll probably agree that they’re not strong enough to actually alter human behaviour.
People sprayed with pheromones have more sex
Oops, spoke too soon! A 1998 study took 38 male volunteers and randomly assigned them an aftershave containing either pheromones or a control substance. The experiment was double-blind, meaning that neither the volunteers nor the scientists knew who had gotten the pheromones.
Before they started using the aftershave, volunteers reported their romantic and sexual activities over a two-week period, providing intimate details on the following encounters:
– formal dates
– informal dates
– sleeping next to a partner
– sexual intercourse
Then they started using the aftershave. And — surprise! — subjects given pheromones were more likely to experience an upturn in their frequency of “sexual intercourse” and “sleeping next to a partner.” That is, pheromones actually increased the likelihood of having sex!
There was no change in the frequency of masturbation, so male libido doesn’t seem to be the deciding factor; instead, the authors conclude that pheromone-splashed males were simply regarded as more attractive by potential suitors.
The study was repeated with 36 female subjects and achieved similar results. Women who added pheromones to their usual perfume were more likely to experience an increase in sexual activity.
But humans may not be able to detect pheromones at all
Apologies in advance, because I’m about to burst your bubble. Despite evidence from the above scientific studies, and many others in the field, not every expert is sold on the idea of human pheromones. There is absolutely no doubt that humans produce substances that, in other species, have a definite pheromonal effect. But we still can’t work out how humans are detecting them.
The primary candidate is the vomeronasal organ, a region of the nose that detects pheromones in many mammal species. In preparation for this blog post, I trawled through a veritable headache of contradictory opinions: some scientists say that humans don’t have a vomeronasal organ, or that it disappears during embryonic development, or that we’ve all got one and it’s non-functioning, or that it’s there and working perfectly fine.
I’d love to put all these feuding scientists into a sandpit and have them battle it out gladiator-style, but unfortunately we must let due process run its course. And, even if the vomeronasal organ isn’t functional in humans, it’s still possible we are detecting pheromones via our main olfactory system. But the evidence is still incomplete, and sometimes science just isn’t clear-cut.
In the meantime, you’re all beautiful people in some way or another. Just get out there and hope for the best.
Andrew Katsis is an MSc candidate in Zoology at the University of Melbourne. For more of his objective musings on human sexual attraction, click here.