Abstract
A dual taxonomy is presented to reconcile robust but incongruous facts about age and antisocial behavior: (1) antisocial behavior shows impressive continuity over time, but (2) the prevalence of antisocial behavior changes dramatically over age, increasing almost tenfold temporarily during adolescence. No previous theory has assimilated both observations. This article suggests that “delinquency” conceals two qualitatively distinct categories of individuals, each with a unique natural history and etiology: 1. a small group engages in antisocial behavior of one sort or another at every life stage, whereas 2. a larger group is antisocial only during adolescence.