TEENAGERS' ENGAGING IN sexual behavior is not a new phenomenon. In every preceding generation at least some teenagers were sexually active. Typically, the parents and teachers of these young people, as well as local medical authorities and community leaders, were concerned about the possible consequences of such behavior, especially unwanted teen pregnancy, abortion, and exposure to venereal diseases, now generally referred to as sexually transmitted diseases (STDs). Such concerns are more prevalent today than ever. All across the United States, large numbers of parents, health officials, and others concerned about sexual issues affecting teens fear the rate of teen sex is increasing and worry about the consequences for young people, their families, and their communities.

In addition to the rising levels of concern from parents and society, the past several decades have witnessed an even more marked change in attitudes toward teen sex, part of a larger transformation...