Just ahead of Valentine's Day, researchers at the University of Toronto Mississauga have some advice for couples: stop counting who did the dishes last.

A study co-authored by UTM psychology professor Emily Impett suggests that partners who expect every favour to be paid back may be wearing down their own relationship over time. UTM shared the findings on Monday, Feb. 9.

What the researchers looked at

The work focuses on what psychologists call exchange orientation, the tendency to expect a direct return from a partner when doing something for them. Impett, who directs UTM's Relationships and Well-Being Laboratory, worked with former UTM graduate student Haeyoung Gideon Park and two researchers from the University of Alberta and the University of Michigan.

The team used data from the German Family Panel, a long-running study of partnerships and family life in Germany that began in 2008 and followed participants for 13 years. They analysed interviews with 7,293 mixed-gender couples. According to UTM, there were too few same-gender couples in the data for a meaningful analysis, though Impett expects the results would apply to them as well.

What they found

In general, the expectation of being paid back faded as relationships went on. The researchers think that may happen as partners grow closer and feel less need to track who gave what.

But couples who were slower to let go of a tit-for-tat approach saw their relationship satisfaction drop more steeply. And couples in which both partners scored high on exchange orientation did not get any boost from being evenly matched.

When your support to your partner is tied to a desire for them to repay you, it can feel less like care and more like leverage.

— Emily Impett, psychology professor, University of Toronto Mississauga

Impett told UTM that constant scorekeeping can push each partner to monitor the balance and enforce fairness, which can make them read each other's actions in a more adversarial way and feel less grateful.

Fairness over the long run

The researchers are not arguing that balance doesn't matter. Impett said couples can keep things fair by taking a longer view of give-and-take and talking openly when care starts to feel one-sided.

Most couples want a sense that their relationship is broadly fair and mutual. So think about whether the relationship is balanced over time, versus in this moment.

— Emily Impett, psychology professor, University of Toronto Mississauga

UTM, on Mississauga Road in the city's west end, is one of three University of Toronto campuses.