98

For decades now, research studies have focused on externalizing behaviors in young children, including elevated levels of noncompliance, temper tantrums, aggression toward peers, overactivity, and impulsivity. Early onset problems are a cause for concern because they can set the stage for more serious disorders in middle childhood and adolescence, including oppositional defiant disorder, conduct disorder, and attention deficit/hyperactivity disorder. It is therefore crucial to determine which children who display problems in toddlerhood or in the preschool period are on a developmental pathway toward more serious and long-term disorders and which children are more likely to be experiencing time-limited adjustment difficulties. Theoretical models in developmental psychopathology analyze the dynamic interactions between various child, parenting, family, and community risk factors that predict the emergence of problems and their exacerbation over time, as well as protective factors that mitigate risk. These models highlighting the developmental processes that underlie the onset of early behavioral problems have implications for prevention, treatment, and social policy.