In a series of related studies that include ES families, Burt and colleagues (Burt et al., 2003; 2005a; 2005b) have shown that as adolescence unfolds, CD and the comorbidity among the childhood disruptive disorders can be attributed in part to the family environment, particularly as it relates to parent-child conflict. Association with antisocial peers, by contrast, does not appear to be causal, indicating instead that disruptive adolescents select or shape (either intentionally or inadvertently) subsequent environmental experiences to increase affiliation with deviant peers (Burt et al., in press).