I think it's common sense, PDQ. When children reach the age when they can procreate, they sure as heck ought to understand that particular function of their bodies. If their parents and teachers haven't given them balanced sex education appropriate to their age level, they're going to pick up all sorts of misconceptions from their friends and learn the rest by experimentation.
There's all kinds of hooey from the naysayers about how our schools are teaching our kids to be homosexuals and encouraging promiscuity, but I think that's a lot of bull. Most teachers I know are good, reasonable people with good values, and I can't believe they're undermining the values of our nation and preaching promiscuity.
My kids learned about promiscuity all on their own....unfortunately. I'm glad they're 30 and out of that phase.