SAN FRANCISCO — A social psychologist testified Friday in a trial challenging California's gay marriage ban that leading mental health associations stopped thinking of homosexuality as a mental illness decades ago.
Lawyers for two same-sex couples suing to overturn the voter-enacted ban called University of California, Davis researcher Gregory Herek as an expert witness to bolster their argument that sexual orientation cannot be easily changed.
Herek said leading mental health groups also take a dim view of therapies aimed at making people heterosexual.
The point is central to the plaintiffs' effort to show that gays deserve the same judicial protection as racial and ethnic minorities.
The trial, now in its ninth day, is the first in a federal court to consider whether state bans on gay marriages are unconstitutional.
The plaintiff's were expected to end their case later in the day, with the defense beginning next week.
Chief U.S. Judge Vaughn Walker said he would delay closing arguments for two weeks after the defense rests so he can have time to review the testimony.
Herek said he recently conducted a survey asking people if they decided to be gay, lesbian or bisexual. Eighty-eight percent of the gay men who responded said they had no choice at all about their sexual orientation. The figure was 68 percent for lesbians.
"The vast majority of lesbians and gay men and bisexuals as well, when asked how much choice they felt they have ... say they have experienced no choice or very little choice about that," Herek said.
Herek also said it's clear that gay men and lesbians are looked down upon and even regarded with disgust because of long-standing social stigmas.
"If two men were to walk down the street holding hands in many places, that would elicit a great deal of negative reaction, and that is an example of the stigma that everyone knows lesbians and gay men experience because they are gay," he said.
Proposition 8 was by definition an extension of embedded social stigmas, he contended.
Howard Nielson Jr., a lawyer for Proposition 8 sponsors, cross-examined Herek about whether sexual orientation is as fixed as Herek implied.
Nielson cited some of Herek's writings stating that some people who regularly engage in sex with people of the same gender do not necessarily identify as gay, while others may have same-sex attractions they never act on.
"Most people display consistency in their attractions and behaviors," Herek said. "We do see some examples where some people express attraction but do not have the sexual behavior."