Women feel calmer after being exposed to their male partner's scent, new research has found. The improvement was observable in their cortisol levels during mock stress trials.
Smell is a powerful driver of emotion and memory. Just a whiff of something your parents used to cook is enough to yank you back to your childhood days, and a hint of a lover's perfume enough to put the spring back in your step. New research shows that smell can also be a very powerful weapon against stress. The scent of your partner can help lower levels of the stress hormone cortisol even when they're not there. But beware -- the scent of a stranger had the opposite effect.
Benefits you can smell
Authors recruited 96 opposite-sex couples for their study. Men were given a clean t-shirt and told to wear it for 24 hours. They were asked not to use deodorant or other scented body products during this time and refrain from smoking and eating certain foods which might influence their scent during this time. The garments were frozen after being worn to preserve the scent.
The women were then randomly assigned to smell a t-shirt that was either unworn, worn by their partner, or one worn by a stranger, without being told which they were given. Afterwards, they underwent a stress test in the form of a mock job interview and a mental math task. Finally, they filled in a questionnaire regarding their stress levels and saliva samples were taken to measure their cortisol levels. The team asked the ladies to sniff-test the t-shirts because they tend to have a better sense of smell than men.
Overall, women who had smelled their partner's shirt felt less stressed -- both before and after the interview and math tests. Interestingly, those who both smelled their partner's shirt and correctly identified who it belonged to, showed the lowest average cortisol levels among all the participants. This latter finding suggests that the stress-reducing benefits are most pronounced when women are also consciously aware of what they're smelling.
"Many people wear their partner's shirt or sleep on their partner's side of the bed when their partner is away, but may not realize why they engage in these behaviours," said lead author Marlise Hofer from the University of British Colombia.
"Our findings suggest that a partner's scent alone, even without their physical presence, can be a powerful tool to help reduce stress."
On the other hand, women who received and smelled a stranger's scent showed higher average cortisol levels throughout all steps of the test.
The authors believe that this effect is tied to old evolutionary pressures. Hofer says that humans fear strangers from a young age, especially strange males, and it's possible that the scent of such individuals triggers a 'fight or flight' response -- whose observed effect is an elevated level of cortisol.
"This could happen without us being fully aware of it," she adds.
The findings are yet to be definitive, however. The sample size is relatively small, and this study only looked at the interaction between smell and cortisol in women -- who were shown to better handle stress. So more research is needed to determine whether it holds true for larger swaths of the population, and in particular, if men experience similar effects.
Still, for now, the findings offer a quick pick-me-up when your boo is out of town. But they could point the way to new stress-management strategies. For example, the team suggests packing an item of clothing that was worn by a loved one when the job takes us far away from home, to help us relax.
The paper "Olfactory cues from romantic partners and strangers influence women’s responses to stress" has been published in the Journal of Personality and Social Psychology.