Do gay and lesbian couples fare better or worse than heterosexual pairs when it comes to lifelong commitment? According to a report from the Williams Institute at the University of California, Los Angeles, each year just over 1 percent of gay and lesbian partnerships dissolve, compared with an annual divorce rate of 2 percent among straight couples. But because the data on gay partnerships are spotty, most experts agree it's too early to tell whether they truly last longer than straight couples' marriages.

However, some research on same-sex couples who are married or in committed relationships suggests that same-sex couples may have a leg up on straight pairs in an area predictive of lasting partnerships: fighting style. In one study, John Gottman, PhD, founder of the Gottman Institute and the University of Washington's Love Lab, compared the interactions and physiological responses of same-sex and heterosexual co-habitating partners while they talked about mundane issues and sensitive ones. He and his colleagues found that gay and lesbian partners brought up relationship problems more lightly and received such comments less defensively than straight couples. Same-sex pairs were also more likely to use humor and affection in their interactions and to be less physiologically aroused in the face of conflict.

"When it comes to emotions, we think these couples may operate with very different principles than straight couples," says Gottman. "Straight couples may have a lot to learn from gay and lesbian relationships" (Journal of Homosexuality, 2003).

More recent analysis of the same data, however, suggests that other patterns of marital conflict are similar across all couples. In that analysis, researchers from the University of California, Berkeley, wanted to see if the tendency for women to push for change in relationships and for men to support the status quo — known as the demand-withdraw pattern — is attributable to innate sex differences, as widely presumed, or a power differential between partners. Their findings supported the latter view (Journal of Homosexuality, 2010).

Overall, say Gottman and others, same-sex partnerships seem to be more similar to heterosexual ones than different. "Gay and lesbian couples, like straight couples, deal with the everyday ups-and-downs of close relationships," he says.

—Anna Miller