For a successful romantic relationship, maintain other friendships.

In a recent study, Lisa Neff, associate professor of human development and family sciences, examined physiological responses to conflicts in relationships and how external friendships affected these responses.

The study participants were married couples who wrote about their relationship experiences every night before bed. In those entries, they assessed conflicts, such as when a partner broke a promise or snapped during a disagreement. In order to measure levels of cortisol, a stress hormone, they collected saliva samples throughout the day.

Every morning, the body’s cortisol levels spike. Then they usually decrease gradually during the day, but if a stressful event occurs, cortisol levels stay high.

The scientists found that when the couple experienced conflict, cortisol levels remained high instead of decreasing. However, if an affected partner was happy with their friends and social support groups, stress did not affect cortisol as much, even with relationship conflict.

“So don’t forsake your friends when you get in a relationship,” Neff said. “They provide an important aspect as well. They help buffer you, they help make you feel better on a physiological level when you have a less than perfect day.”

She explained all couples experience conflict — friends are just one mechanism to cope.

“We’re all human. No one has the perfect partner,” Neff said. 

Another aspect of dealing with conflict in a relationship relates to external stressors. Whenever a couple devotes energy and attention to activities outside the relationship, less energy is available for the relationship itself.

“School is very stressful,” she said. “An example I often give in my classes is exam week. I bet exam week is pretty tough on your relationships.”

Even when it’s difficult, students should practice patience to mitigate conflict, according to Neff. She also explained that accumulating small, happy moments in a relationship can help defend against the negative effects of conflict.

“Did you laugh together today? Did you enjoy a leisure activity today?” Neff said. “It seems mundane, but the more you build up those daily positive experiences, the less upset you are when conflict happens.”

Rene Dailey, associate professor of communication studies, also said couples that deal with conflict well are more likely to have successful relationships. She said happiness is contingent on how couples deal with rough times.

“Enjoy the positives, but don’t forget the negatives,” Dailey said. “It’s great in initial phases to focus on the positive, but if there are stress points, see how your partner reacts to things. Say this becomes your really long-term partner — that’s how they’re going to react in stress. So can you deal with that or negotiate through that?”