Is There a 'Gay Gene'?

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...Full Story