“…Olweus (1979) reported an average correlation of 0.63 (0.79 after correcting for attenuation) between early aggression in childhood or adolescence and later aggression, and longitudinal studies have consistently documented that problem behavior in childhood is predictive of adolescent and adult behavior (e.g., Broidy et al, 2003; Farrington, 2003). In particular, it has been associated with alcohol and drug abuse, criminal behavior, academic failure, antisocial behavior, behavioral issues, depression, suicide, family dysfunction, domestic abuse, injury, neglectful and abusive parenting, and even death (Liu, 2004; Liu, Lewis & Evans, In press). A recent 40-year longitudinal study also showed that these negative outcomes tend to be more problematic for life-course-persistent aggressives (onset in early childhood) than late-onset (early adulthood) aggressives (Huesmann, Dubow, & Boxer, 2009).…”