Dude, You Stink So Good

Please note that the t-shirts purchasable in our Swag Shop do not come with pheromones. You must supply your own (or ask your partner to loan you some).

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“Do you wanna smell my sweaty t-shirt?” That doesn’t sound like a very good pickup line for a guy to use, does it? Well, turns out it might be, depending on how attractive he is.

Socioevolutionary theory predicts that people prefer healthy mates who have characteristics that promote successful reproduction and childrearing. For men’s preferences, these characteristics correspond to many of the things that are connected to women’s attractiveness (but that’s a topic for another day). But, what about women’s preferences for males’ characteristics? It’s been argued that symmetry (e.g., that the left and right sides of  person’s body mirror each other) is a marker of genetic fitness and physical and mental health. Indeed, across species, more symmetrical individuals are preferred mates. This preference for symmetry has been found especially true for males; symmetrical men are more successful in mating than their lopsided counterparts.

How do women detect a healthy, symmetrical mate? Is it by visual cues alone, or are there other mechanisms? It turns out that women can also detect symmetrical men via olfactory cues (i.e., by how they smell).

In the first part a clever study,1 male and female participants’ symmetry and attractiveness were carefully measured, and then they were given a new, clean t-shirt to wear for two consecutive nights while sleeping (sans deodorant, perfumes, or colognes). After the two nights were over, the worn a natural t-shirts were placed and stored in a plastic bag to preserve the odor, or smell, of each individual. In the second part of the study, participants came to the lab and smelled the shirts worn by the opposite sex, and then rated the smell of each shirt on the characteristics of “pleasantness,” “sexiness,” and “intensity.” Female raters were also asked to provide information about their menstrual cycles.

The results showed that women prefer the scent of symmetrical men, but only when they were most fertile (i.e., during ovulation). However, these results don’t replicate for men; guys do not show a scent preference for symmetrical women. These findings suggest that women have a preference for guys with good genes, which is a function of their symmetry, and that women have evolved several mechanisms for determining a dude’s symmetry.

Importantly, this study did not identify the chemical, or “pheromone,” that transmits information about symmetry. Clearly, there was some way that participants were able to assess symmetry from the scent of the t-shirts, but the exact nature of that scent is not yet known. Once it is, however, you can anticipate a huge growth in the cologne industry!

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1Thornhill, R., & Gangestad, S. W. (1999). The scent of symmetry: A human sex pheromone that signals fitness? Evolution and Human Behavior, 20, 175-201.

Dr. Benjamin Le – Science of Relationships articles | Website/CV
Dr. Le’s research focuses on commitment, including the factors associated with commitment and its role in promoting maintenance. He has published on the topics of breakup, geographic separation, infidelity, social networks, cognition, and need fulfillment and emotions in relationships.