There’s a new secret to coping with stress, and, if you can get past the initial, reflexive distaste, it actually might be helpful, or at least explain some of our habits: A new study, published in the Journal of Personality and Social Psychology, found people feel calmer after being exposed to their partner’s scent.

Conversely, being exposed to strangers’ scents was not calming; rather, it had the opposite effect, raising levels of the stress hormone, cortisol.

“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 Marlise Hofer, the study’s lead author and a psychology graduate student at the University of British Columbia. “Our findings suggest that a partner’s scent alone, even without their physical presence, can be a powerful tool to help reduce stress.”

For the study, the researchers recruited 96 opposite-sex couples. Men were given a clean T-shirt to wear for 24 hours, and were told to refrain from using deodorant and scented body products, smoking, and eating certain foods that could affect their scent. The T-shirts were then frozen to preserve the scent.

The women were randomly assigned to smell a T-shirt that was either unworn, or had been worn by their partner or a stranger. (Women were chosen as “smellers” because they tend to have a better sense of smell than men.) The women were not told which they had been given. They then underwent a stress test that involved a mock job interview and a mental math task, and also answered questions about their stress levels and provided saliva samples by which researchers measured their cortisol levels.

The team found that women who had smelled their partner’s shirt felt less stressed both before and after the stress test. Those who both smelled their partner’s shirt and also correctly identified the scent also had lower levels of cortisol, suggesting that the stress relief benefits of a partner’s scent are strongest when women know whom they’re smelling.

Meanwhile, women who had smelled a stranger’s scent had higher cortisol levels throughout the stress test.

It sounds a bit coincidental, but authors say evolution explains why we find our partners’ scents calming.

“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,” said Hofer. “This could happen without us being fully aware of it.”

Frances Chen, the study’s senior author and a psychology professor with the university, said the findings could have practical implications to help people cope with stressful situations when they’re away from loved ones.

“With globalization, people are increasingly traveling for work and moving to new cities,” said Chen. “Our research suggests that something as simple as taking an article of clothing that was worn by your loved one could help lower stress levels when you’re far from home.”