3 Reasons to Give Your Valentine a Smelly, Unwashed T-Shirt 

Smelling a lover's t-shirt may reduce stress, improve sleep, and boost security.

Posted Feb 14, 2020

Instead of sending roses or a box of chocolates to your valentine this year, maybe you should consider going to your hamper, pulling out a smelly, unwashed t-shirt and sending it to your partner in a Ziploc bag with a big bow. Why would you do this? A growing body of evidence suggests that smelling a partner's scent on unwashed clothing can reduce stress, improve sleep, and provide olfactory comfort.

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This week, researchers from the University of British Columbia announced that a recent study on the sleep-improving benefits of using an unwashed t-shirt (worn by your partner) as a pillowcase was accepted for publication in an upcoming issue of Psychological Science.

The UBC researchers found that when someone's partner was not physically present, study participants experienced higher quality sleep when they were exposed to their partner's scent emanating from an unwashed t-shirt used as a pillowcase.

For this study, each of the 155 participants was given identical t-shirts with no scent, a lover's scent, or a stranger's scent and asked to use them as pillowcases on consecutive nights.

The unwashed t-shirts were chock full of odor. Before putting on a clean t-shirt that was to be worn for the next 24 hours, participants' romantic partners agreed to refrain from using any deodorants or scented body products.

During each night of this study, participants slept with different t-shirts as pillowcases without knowing if their partner had worn one of the t-shirts. 

The quality of their sleep was monitored each night using actigraphy (i.e., "sleep watches"), which captured data relating to restlessness and physical movements. In the morning, study participants also filled out a questionnaire to self-report if they felt well-rested or didn't sleep well.

Notably, objective data from the sleep watches indicated that being exposed to a romantic partner's scent throughout the night helped people sleep better and start the day feeling more well-rested.

"One of the most surprising findings is how a romantic partner's scent can improve sleep quality even outside of our conscious awareness," Frances Chen, who is the study's senior author and an associate professor in UBC's department of psychology, said in a news release. "The sleep watch data showed that participants experienced less tossing and turning when exposed to their partners' scent, even if they weren't aware of whose scent they were smelling."

In another study (Hofer et al., 2018), Chen and her UBC colleagues found that perceived stress was reduced when women (n = 96) sniffed a t-shirt that had been worn for 24 hours by their romantic partner. Stress levels were measured prior to being exposed to an acute stressor called the Trier Social Stress Test just after taking a big whiff of a partner's unwashed shirt, a clean shirt, or smelling a stranger's shirt.

"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," Marlise Hofer, who is the study's lead author and a Ph.D. student in social psychology at the University of British Columbia, said in a news release. "Our findings suggest that a partner’s scent alone, even without their physical presence, can be a powerful tool to help reduce stress."

Finally, the third evidence-based reason you might want to give your valentine a smelly, unwashed t-shirt is that olfactory comfort is a significant component of attachment and provides a sense of security during periods of separation.

Another study (McBurney, Shoup, and Streeter, 2006) found that about 50 percent of men and 80 percent of women report intentionally smelling a worn article of clothing from their romantic partner's hamper during times of separation. As the authors explain, "Both men and women reported that smelling an absent partner's clothing made them feel happy, comfortable, and secure." 

If you think that giving your romantic partner an unlaundered t-shirt for Valentine's Day seems weird, you're not alone. That said, if you provide some instructions (e.g., store this in the freezer and use as a pillowcase when we're miles away) your dirty laundry could turn out to be a treasured "gift that keeps giving" much longer than a dozen long-stem roses.

In the event that your partner seems disappointed (or offended) after receiving an article of unwashed laundry in a Ziploc bag: Keep it lighthearted, but also try sharing some of the empirical evidence in the reference box below to support your rationale for giving him or her a smelly and seemingly unromantic Valentine's Day gift.

To cover your bases and avoid ending up in the dog house—in addition to giving your valentine a stinky t-shirt, I'd probably get some sweet-smelling flowers, too, if I were you. 


"Smelling Your Lover's Shirt Could Improve Your Sleep" from UBC Department of Psychology (retrieved February 14, 2020) 

Marlise K. Hofer, Hanne K. Collins, Ashley V. Whillans, Frances S. Chen. "Olfactory Cues From Romantic Partners and Strangers Influence Women’s Responses to Stress." Journal of Personality and Social Psychology (First published: January 4, 2018) DOI: 10.1037/pspa0000110

Donald H. McBurney, Melanie L. Shoup, Sybil A. Streeter. "Olfactory Comfort: Smelling a Partner's Clothing During Periods of Separation." Journal of Applied Social Psychology (First published: August 9, 2006) DOI: 10.1111/j.0021-9029.2006.00105.x