Is There a 'Gay Gene'?

March 26, 2008— -- It's a medical mystery, one of the biggest debates of our time: Is there a gene that determines whether you're gay or straight? Some scientists think so, saying sexual identity is mostly biological. Others say it's a learned behavior.

Not that kids need science to confirm what they already know. Zach O'Connor, now 18, says he knew he was different from the time he was 5 or 6. Most of his friends were girls, and he once asked his parents for a Barbie Dream House.

"I guess I didn't want to associate myself with guys, 'cause I was like, 'well, I don't want any feelings to happen,'" he told us. "'So I'll associate myself with girls."

Zach says he didn't know why he was different. He just knew he liked boys — not romantically, not then. But at about 11, his feelings began to deepen, and around seventh grade he realized he was gay. Two years later he told his mother, whose reaction astounded him.

"She said, 'Have you done your homework?'" Zach said.

"I think he expected me to start getting hysterical or something," recalled Cindy O'Connor. "I said, 'Zach, you know what? Who you choose to love is your business."

Both Cindy and her husband, Dan, believe homosexuality was probably in their son's DNA. For them, there is no medical mystery. But a proven genetic link might help other parents understand what they saw with their own eyes.

Chris and Deborah Hawkins were convinced their son David was gay when he was just 3.

"I saw feminine traits," Deborah said. "He was, like, prissy." She showed us home videos of David as a little boy, pointing out that "his run was a little flamboyant … his walk, his mannerisms."

David, now in his early 20s and openly gay, said he doesn't remember feeling different from his playmates.

"We would play king and queen and of course, I was the king and he was the queen, you know," said his mom, laughing.

"That was my role," recalled David. "I identified more with that kind of personality rather than the gallant hero."