The smell of a man can calm his partner and cause panic in others, according to a small but fragrant body of research. Studies suggest that smell has an impact on sexual selection, and that animals’ stress responses are often tied to a mate’s odor. But scientists suspect the unique power of man smell specifically comes down to its strength — and women’s sensitivity to it.
“Men’s scent is more easily detectable, and women have a better sense of smell than men do,” Frances Chen, a psychology professor at the University of British Columbia, told Fatherly.
Women have more cells in their olfactory bulbs than men, contributing to their peaked sense of smell. George Preti, a chemist and member of the Monell Chemical Senses Center in Philadelphia, confirms that the effects of “man smell” are at least partly because women have superior sniffers — but adds that it’s also just that men are plain smellier. “Young men produce the strongest odor, followed by older men, young women, then older women,” Preti told Fatherly.
The implications of smelly men and superior female sniffers, however, is a relatively new area of research. Chen notes that some studies have demonstrated how the smell of a mother’s milk can reduce stress hormone levels in babies, while lab rats show similar declines in cortisol levels when in the presence of familiar rats, assuming they can smell them. The famous 1995 work known as the “sweaty t-shirt study” also found that when men wore a t-shirt for two days and then put it in a box, women were most attracted to scents genetically different from their own (implying that scent has something to do with smart mating practices). Other research suggests that 80 percent of women intentionally smell their partner’s dirty clothes compared to 50 percent of men.
Chen’s own study on the subject, published in the Journal of Personality and Social Psychology, involved asking men to wear t-shirts for 24 hours without deodorant or scented products, and then randomly assigning heterosexual women to either smell the shirts of their partners or of strangers. Each woman then participated in a mental math test and mock job interview, as researchers monitored their stress levels through interviews and saliva tests.
When women smelled their partners, Chen and colleagues reported, they experienced less stress before and after the stress test, whereas the opposite occurred with smells of unfamiliar men.
While it seems clear that women benefit from smelling their male partners, there is still virtually no research available on how men react to smelling their female partners, Chen notes. Until then, the potentially more subtle effects of female odor remain a redolent mystery.
“We’re currently conducting follow-up studies to see if the stress-reducing effects will also happen if the men are the smellers,” Chen says. “But it’s an open question.”