Aggressive behavior in childhood has long been separated into that which is proactively motivated and that which is reactive. We report a meta-analytic review of the existing empirical literature that examines the associations of each type of aggression with six indices of psychosocial adjustment: internalizing problems, emotional dysregulation and ADHD-type symptoms, delinquent behaviors, prosocial behavior, sociometric status, and peer victimization. Even though not detectable in most single studies, meta-analytic combination revealed that reactive aggression was more strongly related to most of the indices of adjustment than was proactive aggression. This difference was small, however, and we argue that the difficulty in detecting differential correlates is due to the high intercorrelation between the functions of aggression, which appears to be an artifact of traditional measurement procedures. It is recommended that future research use measures that provide distinct assessment of the functions in order to more clearly distinguish the correlates of proactive and reactive aggression. (Contains 2 tables and 3 footnotes.)