What Works for Whom in School-Based Anti-bullying Interventions? An Individual Participant Data Meta-analysis.

The prevalence of bullying worldwide is high (UNESCO, 2018). Over the past decades, many anti-bullying interventions have been developed to remediate this problem. However, we lack insight into for whom these interventions work and what individual intervention components drive the total intervention effects. We conducted a large-scale individual participant data (IPD) meta-analysis using data from 39,793 children and adolescents aged five to 20 years (Mage = 12.58, SD = 2.34) who had participated in quasi-experimental or randomized controlled trials of school-based anti-bullying interventions (i.e., 10 studies testing nine interventions). Multilevel logistic regression analyses showed that anti-bullying interventions significantly reduced self-reported victimization (d = - 0.14) and bullying perpetration (d = - 0.07). Anti-bullying interventions more strongly reduced bullying perpetration in younger participants (i.e., under age 12) and victimization for youth who were more heavily victimized before the intervention. We did not find evidence to show that the inclusion of specific intervention components was related to higher overall intervention effects, except for an iatrogenic effect of non-punitive disciplinary methods-which was strongest for girls. Exploratory analyses suggested that school assemblies and playground supervision may have harmful effects for some, increasing bullying perpetration in youth who already bullied frequently at baseline. In conclusion, school-based anti-bullying interventions are generally effective and work especially well for younger children and youth who are most heavily victimized. Further tailoring of interventions may be necessary to more effectively meet the needs and strengths of specific subgroups of children and adolescents.

Does affirming children's autonomy and prosocial intentions help? A microtrial into intervention component effects to improve psychosocial behavior.

Prior research has related children's prosocial behavior to overall well-being, and stimulating prosocial behavior is the aim of many social-emotional skills interventions. This study assessed if affirming children's autonomy stimulates their psychosocial behavior. We conducted a three-arm microtrial with four repeated measures to assess if a social-emotional skills intervention with an autonomy affirmation component had an additive effect on children's behavior as compared to a "regular" intervention focused exclusively on teaching social-emotional skills and a no-treatment control condition. Our sample consisted of 779 children in Grades 4-6 (Mage = 10.61, SD = 0.93). Findings from latent change modeling demonstrated that the social-emotional skills intervention with an autonomy affirmation component yielded superior effects as compared to the "regular" intervention and the no-treatment control condition on the improvement of internalizing and externalizing problem behavior in the three-month period after the intervention. The intervention with autonomy affirmation did not yield superior effects on prosociality and social skills, self-efficacy, and self-esteem or self-perceived competence. The absence of these effects may be attributed to the dosage of the interventions implemented-the affirmation of children's autonomy may require more than four sessions to sort observable effects. Overall, however, the findings of this study provide an initial suggestion that it may be beneficial to affirm children's autonomy and prosocial intentions when enhancing children's behavior.

Effective Components of Social Skills Training Programs for Children and Adolescents in Nonclinical Samples: A Multilevel Meta-analysis.

Social skills training (SST) programs for nonclinical children and adolescents are known to have positive effects on social skills, but it remains unclear how distinct training components are related to program effects. This multilevel meta-analysis examines how psychoeducation (i.e., exercises aimed at the transfer of knowledge), psychophysical components (i.e., physical exercises aimed at improving self-confidence and trust in others), skill-building components (i.e., exercises aimed at improving interpersonal skills), and cognitive-emotional components (i.e., exercises aimed at changing emotions and cognitions) are independently related to SST program effects. We extracted data from 97 articles describing 839 effect sizes. Training content data were extracted from 60 corresponding SST programs. Our results showed that SST programs had a positive effect on the development of interpersonal skills and emotional skills in nonclinical samples: d = .369, 95% CI [.292, .447], p < .001. This effect was positively influenced by the inclusion of psychoeducation and skill-building components. The inclusion of psychophysical components and the number of cognitive-emotional components did not influence program effects. For psychoeducation and skill-building components, we observed a curvilinear relationship between intensity and effect size: programs including three to six psychoeducational exercises yielded larger effect sizes compared to programs with more or fewer psychoeducational exercises, and programs with 11 to 20 skill-building exercises outperformed programs with more or fewer skill-building exercises. These findings are an indication that psychoeducational components and skill-building components are related to larger SST program effects, granted that the dosage is right.