Want to improve your love life? Do the dishes!

If you do something positive for your mate, does it matter why? The answer is yes, according to new research from University of Rochester research assistant professor Heather Patrick. She shows both small sacrifices, like doing the dishes for your partner; and big ones, like moving across the country for a new job he or she really wants, mean more if you do them because you genuinely want to.

To answer one of the most common conundrums of romantic relationships, Patrick asked 266 men and women in relationships to document either their own or their partner's pro-relationship behaviors (PRB) for two weeks. Pro-relationship behavior can be any sacrifice or accommodation made out of consideration for one's partner or one's relationship.

Patrick found that partners who engaged in PRB because they wanted to -- not because they felt pressured or obligated to -- were more satisfied in their relationships, more committed to them and felt closer to their mates following PRB experiences.

But she also found that people who simply perceived that their partners engaged in PRB because they wanted to were also more satisfied and committed to their relationship after a partner's PRB.

This research illustrates the crux of Self-Determination Theory: A self-motivated person derives more satisfaction in completing a given task, and is more likely to do it well. Patrick says her research has practical applications, and she sees it being used for individual and couples therapy. She says this new information gives couples and psychology professionals insight into why some relationships aren't fulfilling even when everything looks okay on the surface.

"It's important to understand what makes positiverelationships positive, and what might undermine positive experiences," Patrick says.