The latest research out of a Canadian university last week suggested psychology should never underestimate the power of the nose. A recent study from the Department of Psychology at the University of British Columbia (UBC) in Vancouver, Canada, found test participant stress levels could be lowered as a result of access to the aroma of a “romantic partner”. Results of the analysis were published in this month's Journal of Personality and Social Psychology.
According to UBC psychology graduate student and lead author of the study, Marlise Hofer, outcomes from the experiment showed female participants felt calmer after exposure to their male partner’s natural scent. Meanwhile, exposure to the natural scent of a male stranger caused contrary results of increased stress levels and measurably raised production of cortisol, the stress hormone, in female test participants.
“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,” Hofer explained in an article for the UBC News. “Our findings suggest that a partner’s scent alone, even without their physical presence, can be a powerful tool to help reduce stress.”
Researchers worked with a pool of “96 opposite-sex couples”. Since, according to the researchers, the female sense of smell tends to be more sensitive, the female participants were asked to take on the role of the smellers.
Male participants received one clean t-shirt each to wear for a full 24 hours. The men were told not to use any scented personal care products during that time and were instructed not to influence their natural scents by eating certain foods or smoking. After 24 hours of wear, the t-shirts were stored in a frozen state in order to “preserve the scent”.
When the smellers (women) reported for testing, they were not told which of three possible shirts they were given to smell. The possibilities included: an unworn shirt, a shirt worn by a stranger, or a shirt worn by their romantic partner.
After smelling one of the three random shirts, the women’s cortisol levels in their saliva were measured and they participated in a series of stress tests including “a mock job interview and a mental math task, and . . . questions about their stress levels”.
Study findings showed that for women who were given their partner’s shirt to smell, they felt less stress “both before and after the stress test”. Cortisol levels were even more reduced for females who had themselves recognized that the shirt they were smelling belonged to their own partner.
Interestingly, the women who smelled a shirt from a stranger recorded much higher levels of cortisol throughout the post-smell stress tests.
“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,” Hofer speculated. “This could happen without us being fully aware of it.”
UBC psychology assistant professor Frances Chen is also the study’s senior author. She believes the experiment’s results “could have practical implications to help people cope with stressful situations when they’re away from loved ones”.
Chen referred to the influence of globalization and the stressors it can have on modern life. “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.”
The researchers emphasized that their study “speaks to the critical role of human olfactory cues in social communication and reveals that social scents can impact both psychological and physiological reactions to stress.”
In her article for Forbes Magazine in 2016, writer Kristina Moore interviewed Stanford University graduates Erika Shumate and Christine Luby, who had used their post-secondary studies in human olfactory signals to become successful perfumers.
According to Shumate, the olfactory bulb, where smell is processed, is located in the brain’s limbic system in conjunction with the brain’s area for emotional memory. “So literally, your brain is set up to process scent with memory and emotion,” she explained. “Scent is the hardest of the five senses to logically assess due to its close proximity to emotion and far distance from vocabulary and logic processing.”
Like Shumate and Luby, other scientists are recognizing the importance of smell to human wellbeing. In May 2017, Science Magazine writer Lindzi Wessel interviewed neuroscientist John McGann of Rutgers University in New Brunswick, New Jersey who believes “the myth of the nonessential nose is a huge mistake--one that has led scientists to neglect research in a critical and mysterious part of our minds”.
McGann referred to the fact that while the human olfactory abilities have not yet been studied in a “head to head” contest with dogs or other super-olfactory animals, researchers at the University of California, Berkeley, prepared a human smell trail in a field. “They blindfolded undergraduate subjects and gave them earmuffs so they couldn't use any senses other than smell,” he explained. “They found the students were perfectly capable of following the trail out in the field."
Collins, H., & Whillans, A., (January 24, 2018). Stressed out? Try smelling your partner’s shirt. UBC News. https://news.ubc.ca/2018/01/04/stressed-out-try-smelling-your-partners-shirt/
Hofer, M. K., Collins, H. K., Whillans, A. V., & Chen, F. S. (2018). Olfactory cues from romantic partners and strangers influence women’s responses to stress. Journal of Personality and Social Psychology, 114(1), 1-9. http://dx.doi.org/10.1037/pspa0000110
Moore, K., (October 4, 2016). Pinrose Personalized Fragrance Algorhythm Assures Wearers Best Scent. Forbes.com. https://www.forbes.com/sites/forbesstylefile/2016/10/04/designer-spotlight-pinrose-personalized-fragrance-algorithm-assures-wearers-best-scent/#becdbdc1373f
Wessel, L., (May 11, 2017). Your nose knows more than scientists thought. Science Magazine. http://www.sciencemag.org/news/2017/05/your-nose-knows-more-scientists-thought