Longitudinal research indicates that aggressive children are at risk for continuing the coercive lifestyles that engendered their aggressive problems. Children who are aggressive at age 8 have a high probability of extending their aggressive behavior patterns into adulthood. Disruptive and bellicose children have a tendency to become adults who are at risk for marital conflict and child abuse, to engage in criminal behavior, and to become addicted to drugs and/or alcohol (e.g., Farrington, 1991; Huesmann, Eron, Lefkowitz, & Walder, 1984). Although aggressive behavior patterns are remarkably stable (Loeber, 1990; Olweus, 1979), they are expressed differently at various stages of development and are sensitive to different risk factors during those stages (Loeber, 1990). The interaction of individual characteristics with risk factors seems to determine the developmental path for aggressive children. In other words, children's behavioral, affective, and cognitive processes likely affect and are affected by parental and peer influences to direct the life course (Loeber, 1990). In this chapter, we focus on the role of peers in maintaining and exacerbating the developmental course of aggressive children. Peer influence is examined in the context of an intervention designed to interrupt the maladaptive trajectory of aggressive children by improving peer interactions.

Developmental course of aggressive children

Peer relations have been identified as a salient risk factor in the development of aggressive behavior problems. There is growing evidence that peer interaction plays multiple roles in social, cognitive, and moral development.