Today's youths live in a world that sees their rebellious behavior and esoteric lifestyles as a "natural" part of growing up. But this is hardly natural. In effect, adolescence was forged as a social experiment 150 years ago, when school attendance became mandatory beyond puberty. As a result, adolescence came to be marked not only as a separate and troubled period in the lifecycle, but also as an all-encompassing social problem, requiring the intervention...