Childhood externalizing behaviors represent a cluster of behavioral problems consisting of aggressive, hyperactive, and/or disruptive actions (Hinshaw, 1987). Childhood externalizing behaviors are developmental precursors to adolescent and adult problem behaviors such as criminal and violent behavior (Betz, 1995; Farrington, 1989; Moffitt, 1993) and substance use (Timmermans et al., 2008; King et al., 2004; Thompson et al., 2011). Understanding the etiology of externalizing behaviors in childhood has important implications for the development of early interventions that...