Individual Differences in Personality Associated with Aggressive Behavior among Adolescents Referred for Externalizing Behavior Problems

The present study examined the extent to which individual differences in personality that have been previously associated with aggression in non-clinical subjects (Caprara et al., European Journal of Personality, 27(3), 290–303, 2013, Caprara et al., Developmental Psychology, 50(1), 71–85, 2014) account for aggression among adolescents referred to psychiatric services with diagnosis within the externalizing spectrum (i.e., conduct disorder, oppositional defiant disorder, and attention deficit hyperactivity disorder). In particular a conceptual model was examined in which individual differences in basic traits (i.e., emotional instability and agreeableness), lower order traits (i.e., irritability and hostile rumination), and social cognitive mechanisms (i.e., moral disengagement) account for aggressive behavior. One hundred and nine adolescents (81 males, 74.3%), ranging in age from 11 to 18 (M = 13.83, SD = 1.70) and referred to psychiatric services for the above diagnoses, participated at the study. Adolescents filled in questionnaires measuring the Big Five traits, as well as irritability, hostile rumination, and moral disengagement; their parents filled in the Child Behavior Checklist to assess children’s aggressive behavior. Findings corroborated the posited pattern of relations previously found in non-clinical samples. In accordance with those findings, moral disengagement largely mediated the association between traits and aggressive behavior. The model explained a significant portion of variance in aggressive behavior. As a novelty, findings showed a direct association between emotional instability and aggressive behavior, pointing to the major relevance of emotional disregulation in adolescents referred for externalizing problem behaviors in comparison to non-clinical adolescents.