Being committed to your marriage is not just about being faithful to each other but also doing what it takes to make the relationship successful -- the most important thing being 'compromise', researchers say.
The study by UCLA psychologists analysed 172 married couples over the first 11 years of marriage.
"When people say, 'I'm committed to my relationship,' they can mean two things," said study co-author Benjamin Karney, a professor of psychology and co-director of the Relationship Institute at UCLA.
"One thing they can mean is, 'I really like this relationship and want it to continue.' However, commitment is more than just that."
A deeper level of commitment, the psychologists report, is a much better predictor of lower divorce rates and fewer problems in marriage.
"It's easy to be committed to your relationship when it's going well," said senior study author Thomas Bradbury, a psychology professor who co-directs the Relationship Institute.
"As a relationship changes, however, shouldn't you say at some point something like, 'I'm committed to this relationship, but it's not going very well -- I need to have some resolve, make some sacrifices and take the steps I need to take to keep this relationship moving forward. It's not just that I like the relationship, which is true, but that I'm going to step up and take active steps to maintain this relationship, even if it means I'm not going to get my way in certain areas'?"
"This," Bradbury said, "is the other kind of commitment: the difference between 'I like this relationship and I'm committed to it' and 'I'm committed to doing what it takes to make this relationship work.' When you and your partner are struggling a bit, are you going to do what's difficult when you don't want to? At 2 a.m., are you going to feed the baby?"
The couples that were willing to make sacrifices within their relationships were more effective in solving their problems, the psychologists found.
"It's a robust finding," Bradbury said.
"The second kind of commitment predicted lower divorce rates and slower rates of deterioration in the relationship."
Of the 172 married couples in the study, 78.5 percent were still married after 11 years, and 21.5 percent were divorced.
The couples in which both people were willing to make sacrifices for the sake of the marriage were significantly more likely to have lasting and happy marriages, according to Bradbury, Karney and lead study author Dominik Schoebi, a former UCLA postdoctoral scholar who is currently at Switzerland's University of Fribourg.
For the study, the couples � all first-time newlyweds -- were given statements that gauged their level of commitment. They were asked to what extent they agreed or disagreed with statements like "I want my marriage to stay strong no matter what rough times we may encounter," "My marriage is more important to me than almost anything else in my life," "Giving up something for my partner is frequently not worth the trouble" and "It makes me feel good to sacrifice for my partner."
The psychologists videotaped the couples' interactions and measured how they behaved toward each other.
The psychologists also conducted follow-ups with the couples every six months for the first four years (and again later in their marriages).
Bradbury said that in a long-term relationship, both parties cannot always get their way.
"Find ways to compromise, or at least have the conversation that allows you and your partner to see things eye to eye," Bradbury said.
"In a marriage, disagreement is inevitable, but conflict is optional -- a choice we make, Bradbury and Karney added.
The study has been published online in the Journal of Personality and Social Psychology, the premier journal in social psychology.