Results of the study indicate that reactive regression was associated with increases in peer delinquency and peer delinquency was associated with increases in reactive aggression. This suggests that reactive aggression is predictive of increases in reactive aggression. However, proactive aggression and peer delinquency were unrelated. Although research has found that proactive and reactive aggression differentially relates to peer variables, no research has examined how these forms of aggression relate to peer delinquency. This study examined the relation between proactive and reactive aggression and peer delinquency using a 1-year prospective design in a high-risk community sample of 9 through 12 year old children. Tables, notes, and references