In a historic decision Friday, the U.S. Supreme Court ruled that states could not prevent same-sex couples from marrying, and the justices reached that conclusion in part due to the efforts of several associations.

The American Psychological Association was among more than a dozen organizations that filed an amicus brief in the case laying out the scientific evidence that gay relationships are as stable as heterosexual ones.

"Empirical research demonstrates that the psychological and social aspects of committed relationships between same-sex partners largely resemble those of heterosexual partnerships," said APA President Barry Anton said in a statement.

APA once classified homosexuality as a mental disorder, but it has long since rejected that stance. The group has supported legal benefits for same-sex couples since 1997 and civil marriage for gay couples since 2004.

Among the groups that joined APA in the amicus brief were the American Medical Association, American Psychiatric Association and American Psychoanalytic Association, the latter of which called the Supreme Court ruling a "momentous decision."

"Marriage has a profound psychological benefit for married individuals and their families," Mark Smaller, president of the American Psychoanalytic Association, said in a statement. "That is why in 2012, our organization issued a position statement opposing discrimination in civil marriage to same-sex and same-gender couples."

Outside of medical organizations, reaction to the ruling has been muted among associations, which have long been reluctant to weigh in on controversial social issues. There have been exceptions: Earlier this year, ASAE and other business groups were quick to criticize a proposed Indiana "religious freedom" law that could have made it legal for businesses to discriminate against gay people. The law was passed with the offending language removed.

One of the few business groups that have spoken out for same-sex marriage is the Consumer Electronics Association. Last year CEA agreed to donate to the Log Cabin Republicans, a group of gay conservatives, in an effort to nudge the GOP into accepting gay marriage.

"This is a great ruling for business, it's a great ruling for innovation," CEA CEO Gary Shapiro told CEO Update. "We believe businesses now will have the ability to attract employees without regard to where they're headquartered, without regard to the employees' sexual preferences. It allows the best and brightest to be recruited by businesses across the country."

CEA, which is headquartered in Virginia, has lost at least one employee because of that state's former ban on same-sex marriage. Shapiro said other gay employees have refused to live in the state despite the association's best efforts to get them to live close to where they work.

"We felt Virginia was going the wrong direction on gay marriage, and as an employer in Virginia, we took a pretty strong stance it had to be changed," Shapiro said.

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