Prospective studies examining the etiology of externalizing behavior suggest that conduct problems in childhood and adolescence convey risk for a variety of adult externalizing problems, including violence (Farrington, 1989), chronic offending/criminal behavior (Lynam, 1996), and alcohol and substance use, abuse, and dependence (Baer et al., 1995; Englund et al., 2008; Fergusson et al., 2007; Pulkkinen & Pitkänen, 1994). Although mean increases in externalizing behavior are somewhat normative in adolescence (Moffitt, 1993), studies employing person-centered analyses often reveal a subset of individuals who persist in displaying elevated and potentially detrimental levels of externalizing problems well beyond this transition (Bongers et al., 2004; Nagin & Tremblay, 1999). Thus, identifying factors that can differentiate between (1) developmentally normative increases in externalizing behavior and (2) more severe and enduring forms of externalizing problems is particularly important for targeting individuals/populations most amenable to prevention and intervention programming, and for alleviating potentially harmful long-term public health consequences. Toward this end, developmental scientists have argued that etiological models positing functionally interdependent systems of biological, psychological, and environmental influence will best serve to clarify our understanding of behavioral processes (Cairns et al., 1993; Gottlieb, 2001; Wachs, 2000), including the development of externalizing problems.
