Same-sex couples are as committed and happy in their romantic relationships as heterosexual couples, according to two studies in the January issue of the journal Developmental Psychology.

The authors of the studies – researchers from San Diego State University, University of Urbana-Champaign, the University of Washington, and the University of Vermont – say their findings challenge the stereotype that same-sex relationships aren’t as healthy or secure as heterosexual pairings and are therefore not as psychologically healthy.

“The belief that committed same-sex relationships are atypical, psychologically immature, or malevolent contexts of development was not supported by our findings,” said Glenn I. Roisman, the lead author of the first study. “Compared with married individuals, committed gay males and lesbians were not less satisfied with their relationships,” he noted.

The first study compared 30 committed gay male and 30 committed lesbian couples to 50 engaged and 40 older married heterosexual couples, as well as to dating heterosexual couples.

They found that all the couples had positive views of their relationships, but the more committed couples – both gay and straight – resolved conflict better than the heterosexual dating couples.

Roisman added that gay males and lesbians “were generally not different from their committed heterosexual counterparts on how well they interacted with one another, although some evidence emerged the lesbian couples were especially effective at resolving conflict.”

The second study examined how sexual orientation and legal status affected relationship quality. It researched 65 gay male and 138 lesbian couples in civil unions, 23 gay male and 61 lesbian couples not in civil unions, and 55 married heterosexual couples.

Both partners in all of the couples answered questions regarding their demographics, status of their relationship, number of children, sexual behavior, frequency of contact with their parents with and without their partners and perceived social support. Partners in same-sex relationships also answered questions regarding disclosure of their sexual orientation to their family, peers and work associates.

The three-year study found that same-sex couples were similar to heterosexual couples in most relationship areas, and that legal status didn’t seem to be the overriding factor affecting same-sex relationships.

Couples with civil unions showed no differences on any of the relationship measures as compared with same-sex couples in committed relationships but not civil unions. “This may be because those couples in Vermont who sought out the legal protection of a civil union might have legalized their relationship more for symbolic value than for commitment reasons, which did not affect their day-to-day interactions,” said lead author of the second study, Kimberly F. Balsam.

However, the study found that same sex-couples not in civil unions were more likely to have ended their relationships compared to couples in same-sex civil unions or heterosexual marriages. This suggests that the protections afforded by a legalized relationship may affect same-sex relationships, the authors said

“Gay and lesbian people fall in love. We settle down. We commit our lives to one another. We raise our children. We protect them. We try to be good citizens,” said California Sen. Sheila Kuehl. “Yet not being allowed to legally marry carries dire consequences for committed gays.”

Balsam said the study’s authors plan to follow up on such effects in future research.

Regardless of legal status, same-sex couples reported more satisfaction with their relationships, more positive feelings toward their partners, and less conflict than married heterosexual couples.

The authors theorized that societal pressures and norms, as well as being legally bound to each other may contribute to heterosexual couple’s longevity, even if they are not happy. By comparison, most long-term same-sex couples have to stay together by their own will and hard work, since they don’t have societal sanctions on their side, Balsam added.

The study is the first to follow same-sex couples in legalized unions over a period of time. The research design allowed the researchers to monitor changes in the relationships experienced by both same-sex couples not in civil unions and heterosexual couples. All the couples studied were similar with respect to race/ethnicity and age.