First steps to misbehaving : The co-development of early adolescent friendship and externalizing behavior

The increase in externalizing behaviors such as antisocial behavior, alcohol use, and tobacco use during adolescence, and the role of peers in this increase of externalizing behavior, has been explained by Moffitt’s (1993) dual-taxonomy model. This model assumes that adolescents who start to feel biologically mature but have not yet obtained a socially mature status in society engage in externalizing behavior to obtain a mature status among peers. At the start of adolescence, this study investigated whether (1) early adolescents who are experienced in externalizing behavior have a higher status among peers, (2) whether early adolescents copy the start of or the further (dis)engagement in externalizing from their friends, and (3) whether individual characteristics such as social status, pubertal development, self-control, or music preference impact the co-development of early adolescent friendship and externalizing behavior. In line with expectations early adolescents who were experienced in externalizing behavior were likely to be popular, but less liked, among their peers. Thus it seems that adolescents with an early onset of externalizing behavior become role models to their peers, even though they are less liked and don’t have as many friends as their peers. Although friends did not seem to influence one another in the onset of externalizing behavior, friendship influences in the further continuation of this behavior seemed to be very important. Possibly not same-age friends, but others impact the onset of externalizing behavior. Parents are known to influence the onset of alcohol use, and possibly siblings or friends outside of school could also impact the onset of externalizing behavior. Several individual characteristics had an impact on the co-development of friendship and externalizing behavior. First, early adolescents were especially likely to be influenced by popular friends. Likeability, in contrast, did not affect these peer influence processes. Second, especially early adolescents who engaged in externalizing behavior and had an early pubertal development were likely to remain friends with peers based on similarity in externalizing behavior and thus break friendships with dissimilar peers. However, adolescents with an early pubertal development were not more likely to create friendships based on similarity in externalizing behavior nor did pubertal development impact the development of externalizing behavior. Third, at least in some friendship networks, adolescents with a low self-control were more likely to develop externalizing behavior; regardless of their friends externalizing behavior. Thus self-control impacts adolescents development of externalizing behavior, but not their susceptibility to friendship influence. Fourth, music Preference (Chapter 8) was expected to work as a ‘badge’ which signals belonging to a specific peer group, which in turn might influence behaviors within such groups. Indeed, preference for non-normative music, specifically dance music, was predictive of further engagement in externalizing behavior. In sum, early adolescents who are experienced in externalizing behavior are more likely to be popular than their peers. Furthermore, early adolescents influence their friends in the (dis)continuation but not in the onset of externalizing behavior. Last, individual characteristics impact the co-development of early adolescent friendship and externalizing behavior