Jan 8, 2012
Men's shaved armpits smell better to women as compared to wildly grown ones, a new study has found.
For the study, a group of scientists from Czech Republic had male participants shave one armpit and let the other grow wild.
The researchers then collected odour samples from each of the men's pits and passed them under the noses of a group of females, who then rated how attractive they found each odour.
They found that the women preferred the smell of the shaved pits, but just barely.
"Altogether, the effect of shaving is not quite large," Livescience quoted Jan Havlicek, the lead researcher from Charles University in Prague as saying.
According to Havlicek, the effect of shaving was "transient".
The researchers also found that the study's female participants found the smell of freshly shaven pits more pleasant than pits that had been growing hair for six to 10 weeks, but they could not distinguish between the smell of armpits that had one week of growth and those that had six to 10 weeks of growth.
Any hair, whether short and prickly or long and waxen, smelled about the same.
"This is kind of surprising because when you look at armpit hair after one week, it is only a couple of millimeters long, so that was an unexpected result," he said.
Most interesting of all is that females have a slight preference for shaved armpits over hairy ones, despite the evidence that strongly suggests hairy pits specifically evolved to make people smell more attractive
Scientists think that human armpit hair, longer than that of any other apes, evolved to retain chemicals that are produced copiously by armpit glands, so as to intensify people's natural body odour and increase the chance that others will smell it, and like it.
It is, thus, counterintuitive that women have now come to favour the less intense smell of hairless underarms.
"It's because of cultural beliefs. It is to some extent independent of evolutionary processes and these things which evolved for a much longer time.
"And also this is more related to visual images of shaved and unshaved armpits and how we construct beauty in our cultural context," he added.
The study has been published online in the peer-reviewed journal Behavioral Ecology and Sociobiology.