To our knowledge, there is little evidence of developmental heterogeneity in general externalizing problems across adolescence. That is, early discussions of discrete developmental trajectories pertained solely to behavior at the extremes of the externalizing continuum, such as criminal offenses (Moffitt, 1993). More recently, however, developmental heterogeneity has been identified within the literature on specific, but less extreme forms of externalizing problems. For example, in most externalizing domains the majority of individuals (belonging to one or more distinct groups) will display some measure of increase in their mean levels of externalizing behavior during the early stages of development, peak sometime during adolescence, and then gradually desist from the problem behavior as they move into later adolescence or early adulthood. At the same time, there is typically a much smaller subpopulation of individuals showing heterotypic continuity; that is, they persist in displaying externalizing problems, though the specific behaviors may morph to more appropriately reflect the present developmental period (Kagan, 1969; Kagan & Moss, 1983). Two studies examining adolescents within non-selected samples of European Americans have found distinct subgroups exhibiting persistently elevated levels
