Women who smell attractive to men are more likely to be highly fertile, scientists have found.
A new study revealed a close correlation between feminine odours that male participants judged pleasant and hormone combinations that indicate a good chance of getting pregnant.
Previous research has identified a link between perceived facial and bodily attractiveness in women and hormones relating to fertility.
But the new experiment, published in the Proceedings of the Royal Society B, is the first of its kind to indicate that the link also exists for smell.
Its authors believe that, as in the animal kingdom, humans subconsciously use chemicals detectable by smell to communicate their reproductive ability, and that the genes of women who smell attractive are more likely to propagate because men will be more motivated to procreate with them.
The study also showed that, as with facial and bodily attractiveness, men show a high degree of agreement as to which odours they considered more or less desirable.
“Smelling another person’s body odour can be a poignant and sexually arousing experience, or it can be rather unpleasant and off-putting,” the authors wrote. “These findings provide evidence that body odours act as a valid cue to potential fertility.”
The study was based on 57 men rating the odours of 28 healthy women of naturally reproductive age.
The women adheared to a strict schedule of dietary and behavioural restrictions in order to remove factors that would distort the results.
Body smell was collected from under the armpits using cotton pads in the hours after the women washed with odourless soap.
Meanwhile the women’s hormone levels were monitored. The samples were stored and then smelled by men who rated the odours for attractiveness. In each session, the men rated the odours of 14 different women at a time.
The higher the woman’s level of estradiol, a sex hormone produced in the ovaries which plays a role in determining breast shape and the distribution of flesh around the hips, the more likely she was to be fertile.
The results also linked low progesterone levels with attractiveness. “Chemical communication of sex and reproductive stage are ubiquitous in the animal kingdom, facilitating sexual selection that arises through competition over mates,” the research team wrote.
“Our results provide strong evidence that humans also use chemical signals to communicate reproductive potential.”
The main source of human body odour are the apocrine sweat glands, with an individual’s characteristic body odour resulting from various bacteria operating upon the viscous secretions of these glands, producing a complex mixture of volatile organic compounds.
Other candidates that contribute to body odour are odorous steroids and unsaturated fatty acids.