This dissertation examined the effectiveness of social skills training (SST) for juvenile delinquents. In a matched controlled trial, the effectiveness of Tools4U, an SST that is imposed as a penal sanction for delinquent adolescents in The Netherlands, was investigated. Treatment integrity was considered sufficient to be able to attribute treatment effects to the treatment. The effects on social cognitive outcomes were examined immediately after treatment. Moderator analyses were conducted for demographic and offense characteristics. Furthermore, the influence of treatment motivation and affective empathy on post-treatment skills was examined. Next, the effects on official criminal recidivism about a year and a half after treatment were studied. Finally, a meta-analytic review was conducted to examine the empirical support for the effectiveness of SSTs with juvenile offenders.
Immediately after treatment, Tools4U showed small to moderate positive effects on four outcomes variables (impulsivity, hostile intent attribution, cognitive distortions of self-centering and assuming the worst), no effects on eight outcomes, and negative effects on two outcomes. Only few moderating effects were found: Tools4U improved parental rewarding for parents of girls, confrontational problem-solving for at least moderately motivated juveniles, and decreased hostile intent attribution for juveniles with at least a moderate level of affective empathy. At follow-up no significant treatment effects were found on criminal recidivism. Finally, the meta-analytic review yielded only small overall significant effects for SSTs on offending and social skills, but not on externalizing and internalizing problems. Implications for theory and practice concerning the use of SST for juvenile offenders are discussed.