Joining and Leaving Gangs Selection and Facilitation Effects on Self-Reported Antisocial Behaviour in Early Adolescence

Gang membership is repeatedly reported to be one of the strongest predictors of antisocial behaviour. However, whether this association primarily reflects a selection effect or whether it primarily is related to a facilitation of antisocial behaviour within the gang has scarcely been an object of empirical study. This paper examines how antisocial behaviour and gang membership are associated among adolescents across time, using longitudinal data from a representative sample of Norwegian adolescents (N= 1203). Initial cross-group comparisons revealed that gang members were markedly more involved in general antisocial behaviour than non-gang members not only during periods of active gang membership but also during other periods, thereby supporting the theory that there is a selection effect. This effect was smaller for violence than for other forms of antisocial behaviour. Results from longitudinal analyses that compared behavioural changes among gang members and non-gang members during periods when the gan...