Sharing happy moments with a partner may be good for older people's health

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, according to research published by the American Psychological Association.

We know from lots of research that positive emotions like happiness, joy, love and excitement are good for our health -- they've even been linked to living longer. But most of this research looks at people's emotions as if they happen in isolation. In real life, though, our most powerful positive emotions often happen when we're connecting with someone else. 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."

Tomiko Yoneda, PhD, study lead author of the University of California Davis 

To study this, Yoneda and her colleagues 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 ages 56 and 89. In all three studies, participants provided background and demographic information, then answered short electronic surveys about their emotional state between five and seven 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. 

The researchers found that 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). The research was published in the Journal of Personality and Social Psychology.

"There was something uniquely powerful about sharing those positive emotions together. Even more exciting, we found signs that these shared positive moments have lasting effects," Yoneda said. "When couples felt good together, their cortisol levels stayed lower later in the day. This suggests that co-experiencing positive emotions might actually help the body stay calmer over time." 

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. 

"This work builds on positivity resonance theory, which suggests that when people share positive emotions - along with caring, synchronized connection - it can boost emotional and physiological well-being," Yoneda said. "And according to the theory, those moments can happen between any two people, not just romantic partners. That opens up a whole world of possibilities for future research."