Psychologists' research helped to convince the U.S. Supreme Court to declare the federal Defense of Marriage Act (DOMA) unconstitutional, according to Nathalie Gilfoyle, JD, APA's general counsel.

"There is no question that the social science research presented by APA and its [partners] created a different context for the court to view lesbian and gay couples than the stereotypes employed by opponents of marriage equality," says Gilfoyle. "Justice Anthony Kennedy's majority opinion in the DOMA case showed particular understanding of the stigma associated with second-class citizenship and its negative effects on parents as well as their children."

APA filed amicus briefs in both same-sex marriage cases the court decided in June. In U.S. v. Windsor, which challenged DOMA, the court found that there was no legitimate reason to deny same-sex couples equal treatment under federal law. In Hollingsworth v. Perry, which challenged California's Proposition 8, the court found that the petitioners in the case lacked legal standing to challenge a lower court decision that deemed the referendum unconstitutional.

In its amicus briefs, APA outlined the scientific evidence strongly supporting the idea that homosexuality is a normal expression of human sexuality and is not something individuals generally choose. The briefs also note that there is no evidence that same-sex couples are less fit to be parents or that their children are less psychologically healthy. As the DOMA amicus brief states, "[G]ay and lesbian people form stable, committed relationships that are equivalent to heterosexual relationships in essential respects."

That's certainly true of DOMA plaintiff Edie Windsor and her wife, clinical psychologist Thea Spyer, PhD. They considered themselves engaged in 1967, when same-sex marriage did not exist and married 40 years later. When Spyer died, Windsor was forced to pay $363,000 in federal estate taxes — money she would not have had to pay had she been married to a man rather than a woman. As Windsor told CNN, "This was not only painful, it was wrong."

APA has a long history of support for equal access to legal marriage, adopting policy statements, lobbying Congress and filing amicus briefs in state-level legal cases.

That tradition will continue, says Gilfoyle.

"Consistent with the Supreme Court's decision in the Hollingsworth case, the battle will now move to the states," she says. APA plans to file amicus briefs in the next two cases hitting the courts, in Hawaii and Nevada. "They will be the first cases to look at these issues with the benefit of the Supreme Court's ruling," says Gilfoyle.

— Rebecca A. Clay