Even presidents don’t have an answer to questions about the origin of homosexuality.
And it’s no wonder. Science doesn’t have a clear answer either.
During the third presidential debate, moderator and CBS News correspondent Bob Schieffer asked the candidates, “Do you believe homosexuality is a choice?”
“You know, Bob, I don’t know. I just don’t know,” said President Bush, who then urged tolerance, respect and dignity for homosexuals.
“We’re all God’s children,” answered Sen. John Kerry, the Democratic presidential nominee. Referring to Mary Cheney, the lesbian daughter of Vice President Dick Cheney, Mr. Kerry said, “She would tell you that she’s being… who she was born as. I think if you talk to anybody, it’s not choice.”
So what does science say?
Is homosexuality inborn? Is it caused by outside influences? And, regardless of where it comes from, can it be changed? The answer to all three questions is: yes and no.
If lawmakers, judges, educators and the public are frustrated by such answers, it’s because they’ve been bombarded all year by supporters and opponents of same-sex “marriage,” who have boiled research down to their favorite sound bites.
“Decades of research all point to the fact that sexual orientation is not a choice and that a person’s sexual orientation cannot be changed,” say homosexual rights groups such as Human Rights Campaign, which are flanked by the nation’s premier medical, mental-health and therapy professional groups.
“There is no scientific research indicating a biological or genetic cause for homosexuality,” counters the National Association for Research & Therapy of Homosexuality (NARTH). Homosexuals who want to “can grow into their heterosexual potential” through “psychological therapy, spirituality and ex-gay support groups,” adds NARTH, which has allies in traditional-values and religious groups.
Research supports both camps, but is far more vague, nuanced and unsettled than either lets on.
Science has been searching for the origins of homosexuality since at least the 1930s, when early endocrinologists were hoping to find a glandular explanation for homosexuality. In the early 1990s, science seemed on the verge of finding a “gay gene” or, as Mr. Kerry referred to, some inborn, biological basis for homosexuality, akin to eye color or height.
However, none of the “gay gene” studies have panned out. Even a 2000 study of nearly 5,000 Australian twins showed that, despite having identical genes, only 20 percent of male homosexuals and 24 percent of female homosexuals had a homosexual twin. To many researchers, these findings strengthen the argument that homosexuality stems more from outside influences than inborn genetics.
What are scientists studying today?
A short list might include the effects of hormones in the womb on a child’s sexuality.
Studies have shown that a significant number — as much as 15 percent — of homosexual men have older brothers.
It’s possible, said University of Toronto psychology professor Ray Blanchard and others, that hormonal changes which occur in a mother’s immune system after having several male children might affect a later-born son and somehow predispose him to homosexuality.
If the odds of homosexuality are roughly 3 percent for first-born sons, it might go “to 4 percent for the second [son] to 5 percent for the third,” Mr. Blanchard told Psychology Today magazine.
“Although it has been well established that older brothers increase the odds of homosexuality in men, the route by which this occurs has not been resolved,” noted Northwestern University professor J. Michael Bailey and colleagues in their 10-year review of biological research on human sexual orientation, published in 2002 by the Society for the Scientific Study of Sexuality.
Meanwhile, Cornell University psychology professor Daryl J. Bem has theorized that biologically inherited temperament, played out through life experiences, determine sexual attraction.
His “Exotic Becomes Erotic” theory says that people become “erotically attached” to those “from whom they felt different during childhood.”
Most boys find girls to be different, novel or “exotic,” as Mr. Bem calls it. In a typical heterosexual scenario, girls’ exotic stimuli produces nonsexual physical arousal in boys. If a boy thinks he is with a potential sexual partner, the physical arousal he feels can become an erotic attraction.
However, if a boy grows up feeling “different” from other boys — which might happen to a boy with a gentle or artistic temperament — he may come to view other boys as different, novel or “exotic.” This may explain how men develop erotic attachments to other men, says Mr. Bem, who invites more research into his theory.
Finally, given a renewed interest in bisexuality and transgenderism, as well as lesbianism, more questions are being raised about the changeability or “plasticity” of sexuality.
“Lesbian women consistently report more heterosexual experiences than gay men do, and, after self-identifying as a lesbian, report some degree of opposite-sex attraction,” Mr. Bailey and his colleagues wrote in their 2002 review. “The relationship between sexual plasticity and sexual orientation in women has yet to be explored.”