Sharing happy moments with a partner may be good for older people’s health, lowering the level of the stress hormone cortisol in their bodies, a new study suggests,

 “In real life, our most powerful positive emotions often happen when we’re connecting with someone else,"  said study lead author Tomiko Yoneda, PhD, of the University of California Davis. "We wanted to understand how often older couples share positive emotional moments in their everyday lives, and whether these shared moments affect the body in meaningful ways.”

To study this, the researchers looked at levels of cortisol in older adults. They examined data from three studies with a total of 642 participants (321 cohabitating couples) in Canada and Germany. All the participants were between the ages of 56 and 89. In all three studies, participants provided background and demographic information, then answered short electronic surveys about their emotional state between 5 and 7 times per day for one week.

The surveys focused on positive emotions, asking participants how happy, relaxed and interested they felt at that moment. After each short survey, participants collected a saliva sample using a saliva test strip. The researchers collected 23,931 separate measurements in all.

On occasions when both partners were together and reported positive emotions, participants’ saliva samples showed lower cortisol levels – and this effect was beyond individually experienced positive emotions. The results held true after accounting for several factors that can influence cortisol levels, including age, sex, medications and daily cortisol fluctuations (cortisol levels tend to be higher in the morning).

Perhaps surprisingly, the effect showed up regardless of how satisfied people were with their relationship. In other words, even if a couple wasn’t feeling especially happy with their relationship overall, sharing positive emotions still seemed to have a calming effect on the body.

In the future, Yoneda says, she would like to examine shared positive emotions outside of couples, including among friends, coworkers and family members.

To download a pdf of the study, published in the Journal of Personality and Social Psychology, click here