Instrumental and hostile aggression in childhood disruptive behavior disorders

An analogue task of instrumental and hostile aggression during a competitive game was evaluated in a sample of clinically-referred 8-to 12-year-old aggressive boys. Similar to a prior task in a normative sample (Having, Wallace, & La Forme, 1979), both types of aggression increased during provocation as compared to baseline, indicating the success of the provocation manipulation, with moderate correlations between the two aggressive responses. The aggressive group with attention-deficit hyperactivity disorder (ADHD) and the aggressive group without ADHD each had higher rates of instrumental aggression than controls. Only the aggressive/ADHD group had higher rates of hostile aggression than controls. Parent Child Behavior Checklist ratings indicated a modest but significant unique relationship between instrumental aggression and delinquency. The high rate of both types of aggression in the aggressive/ADHD group suggests that comorbid ADHD and aggression may result in qualitative differences in aggressive behavior. The high rate of hostile aggression in the aggressive-ADHD group supports theoretical assumptions regarding the relationship of hostile aggression to poor impulse control.This research was supported in part by grants to the first author from the Medical College of Pennsylvania, the Allegheny-Singer Research Institute, NIMH First Award (MH4682), and support from NICHD Mental Retardation Research Center Core Center Grant (DH26979); and NIMH grants (MH40364 and MH00590) awarded to the second author. The authors are grateful to Marianne Torchinsky and Abby Michaleski for assistance in data collection. Preliminary data were presented at the annual meetings of the Association for Advancement of Behavior Therapy, New York, November 1988, and the Society for Research in Child and Adolescent Psychopathology, Costa Mesa, CA, January 1990.