In the study, led by Caroline Allen from the University of Stirling in Scotland, about 230 male and female participants were asked to rate the femininity or masculinity of 20 men and 20 women based on photographs and odor samples. Odor samples were obtained by asking these men and women to wear a cotton pad in their armpits for 24 hours. People provided samples once while wearing no deodorant, and then once again after having applied their usual product.
It turns out that men and women have very different ideas of what makes you sexy, at least when smells are involved. For men, femininity is important, as it indicates fertility in a female, but women are looking for masculinity in men, as this suggests they can out-compete other males and provide for offspring, Allen explained.
Female participants rated men as more masculine when wearing deodorant, but only when the men were not so masculine.
"This is suggesting that men with low masculinity can improve levels of masculinity by wearing a deodorant, making them smell as masculine as a highly masculine man,” Allen said. However, men with a highly masculine face and smell were just as masculine with or without deodorant.
Now, for men, things went down a bit differently: They didn’t really care how women (or men) smelled. Men rated male and female participants equally regardless of whether they were using deodorant or not.
According to Allen, this notable difference between men and women supports previous finding suggesting that women are more sensitive or more attentive to smell cues than males. “In general, women are more smell oriented than men. They typically perform better on odor identification tests, odor detection threshold tests and odor memory tests. These effects occur soon after birth,” said Richard Doty, director of the Smell and Taste Center at the University of Pennsylvania and author of “The Great Pheromone Myth.”
Tristram Wyatt, a researcher from the University of Oxford, said the findings also support previous work showing we have ingrained expectations about how men should smell.
“The study is intriguing as it relates to the cultural influences on the ways we use deodorants,” he said.
One hypothesis proposed by Allen to explain these results says that masculinity is a bit like a double-edged sword. If you are a masculine type of fellow, you could be seen as someone who can provide for your partner or family. But a bit too much masculinity can make you look uncooperative and aggressive. This means that there may be an optimal level of masculinity, and for those men who score low on that realm, some deodorant can put them right on the ideal level of masculinity.
But Allen argues that this is not the case for femininity. Women can be as feminine as they want, without any negative consequences. “We hypothesis that this may reflect a difference in the design of male and female deodorants, with there being an optimum level of masculinity, unlike with femininity. If this is the case then our evolved preferences have been shaping our cultural practices [for fragrance design and use],” Allen explained.
Wyatt, however, warned that the results are not so clear cut. “With the small sample sizes, the results are intriguing but not conclusive in biological terms despite some of the statistical significance of some of the results," Wyatt said. So further research replicating these findings with a larger number of odor donors is required.
Allen plans to focus the next stage of her research on how deodorants and other artificial fragrances can alter our perception of other traits, such as health, general attractiveness and fertility, among others. All these traits are related to different aspects of body odors and wearing deodorant or other fragrances may alter how we perceive these traits also.
“We need to investigate how artificial fragrances affect our perceptions of these [traits] to fully assess whether humans are capable of obtaining useful information from body odor in society today," she said.