“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 behaviors,” says Marlise Hofer, a graduate student in the University of British Columbia’s department of psychology and the lead author of a new study published in the Journal of Personality and Social Psychology. Her findings suggest that simply the smelling the scent of your partner – even when they’re not present – can help reduce stress levels.
The study found that women feel calmer when exposed to their male partner’s scent, but when they are exposed to a stranger’s scent, their stress level increases.
In their study, the researchers recruited 96 opposite-sex couples and gave the men a clean T-shirt to wear for 24 hours. The male subjects had to refrain from using deodorant and scented body products, smoking, and eating certain foods that could affect their scent. After 24 hours, the shirts were frozen to preserve the scent. The women were then randomly assigned to smell a shirt that was either unworn, worn by a stranger, or worn by their partner – without being told which one they were given.
The women then underwent a stress test that included a mock job interview and a mental math task, as well as answer questions about their stress levels and have saliva samples taken to measure their cortisol levels. Cortisol is a stress hormone that the researchers used to determine stress hormones in the female subjects.
The results showed that women who smelled their partner’s shirt felt less stressed both before and after the stress test. Furthermore, those who smelled their partner’s shirt and correctly identified the scent also had lower levels of cortisol, which suggests that the stress-reducing benefits of a partner’s scent are strongest when women know what they’re smelling. Not surprisingly, women who had smelled a stranger’s scent had significantly higher cortisol levels during the stress test.
From these results, the study’s authors believe that evolutionary factors may influence the mechanisms behind why a stranger’s scent raised cortisol levels. “From a young age, humans fear strangers, especially strange males, so it is possible that a strange male scent triggers the ‘fight or flight’ response that leads to elevated cortisol,” says Hofer. “This could happen without us being fully aware of it.”
The authors believe that these findings could have practical applications to help individuals cope with stressful situations when they are away from their loved ones. Long distance relationships and travel for work can separate couples for extended periods of time. Doing something as simple as wearing an article of clothing worn by your partner may help you deal with stress more effectively while they’re away.