What is it about sex education that causes some otherwise rational adults to behave irrationally? When it comes to other topics -- smoking, drinking, drug abuse -- we don’t hesitate to give our children the benefit of an unambiguous “no.” We tell them flat out that they shouldn’t do it. If anyone said, “But kids are going to drink any way, so let’s show them how they can minimize the effects of a hangover,” most parents would suggest that that person have his head examined. Yet who can deny that the same logic (or lack thereof) lies behind the push...