Just days after U.S. District Judge Vaughn Walker struck down California’s constitutional amendment banning same-sex marriage, APA President Carol D. Goodheart, EdD, opened a series of APA Annual Convention sessions highlighting what psychological science can add to the public debate over same-sex marriage.

“The fact that we’re meeting in this state has given us an unmatched opportunity to focus public attention on the scientific research into the benefits to mental health of marriage, and conversely, on the pernicious health effects of discrimination and stigma,” Goodheart said.

California continues to be a key battleground state for same-sex marriage. Although the State Assembly approved legislation allowing same-sex marriage in 2005 and 2007, Gov. Arnold Schwarzenegger (R) vetoed both measures, and the question moved to the courts.

After the California Supreme Court ruled in May 2008 that denying same-sex couples marriage rights was unconstitutional, more than 18,000 same-sex couples got married in the next six months. In November 2008, California voters approved Proposition 8, the state constitutional amendment prohibiting same-sex marriage. Walker ruled that the amendment was unconstitutional Aug. 4.

Annual Convention speaker Gregory M. Herek, PhD, of the University of California, Davis, who had spent a day on the stand as an expert witness for plaintiffs seeking to overturn the California amendment, talked about the questions he’s most often asked when courts examine same-sex marriage laws.

He’s usually asked if there is such a thing as sexual orientation, and how to define it. Herek testifies that attraction to the same sex is a normal expression of human sexuality, and that most people are consistent in their sexual orientation and report that they did not experience their orientation as a choice. Interventions to change sexual orientation are unlikely to reduce same-sex attraction, and often cause considerable psychological distress when they fail, he said.

In previous testimony, he’s made the point that legally married couples get access to special rights and privileges, enjoy greater relationship stability and receive social support and recognition, and that restricting marriage to opposite-sex couples is an expression of stigma.

“Denying gays and lesbians access to the institution deprives them of those benefits,” he said.

Other psychologists at the sessions discussed results from research on homosexuality, including:

  • The impact of stigma. Laws that exclude lesbian, gay and bisexual people from marriage cause stress, and that stress negatively impacts physical and mental health, said Ilan Meyer, PhD, of Columbia University. The experience of living with stigma, always being vigilant and constantly needing to conceal your “authentic self” from disapproval and even violence exacerbates the pressures that everyone feels in daily life, he said.

    “The impact of not being able to express who you are has very dangerous health effects,” he said.

  • The strengths of same-sex relationships. Surveys conducted in California showed that 75 percent of lesbians and more than half of gay men were in a relationship with one person, said Letitia Anne Peplau, PhD, of the University of California, Los Angeles. Data also show that similar to heterosexuals, many lesbians and gay men date in their 20s, settle down into a relationship in their 30s and maintain it long-term.

  • How children fare. Research shows that children raised by lesbian and gay parents develop in the same positive ways that children raised by heterosexual parents do, and that same-sex couples are just as capable of providing a supportive environment for children, said Charlotte J. Patterson, PhD, of the University of Virginia.

    Research also shows that same-sex couples can effectively parent adopted children, Patterson said (see "Adopted children thrive in same-sex households, study shows").

  • Love and marriage. When same-sex couples have the opportunity to get legally married, they run out and say, ‘I do,’ said M.V. Lee Badgett, PhD, an economist at the University of Massachusetts, Amherst. In contrast, civil unions and domestic partnerships are not viewed as having the same emotional weight, social approval and legal protections as marriage, Badgett said.

“It’s clear that same-sex couples are voting with their feet, in terms of which status they think is more important,” she said.