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

Abstract

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.

Interventions That Failed: Factors Associated with the Continuation of Bullying After a Targeted Intervention

“…The likelihood that the intervention would fail increased as the students got older. This finding is consistent with the results of Johander et al (2021) who found that targeted interventions were less effective in secondary schools compared to primary schools, as well as meta-analyses indicating that whole-school antibullying programs tend to work better among younger students (e.g., Hensums et al, 2022;Yeager et al, 2015). According to the present findings, however, it is not only a matter of primary schools having a greater capacity than secondary schools for dealing with bullying, but of developmental differences as well; every additional year made the intervention failure more likely.…”

“…The age of the students involved appears to play a role in how successful adult interventions are at stopping bullying and therefore victimization. Previous research has shown that both whole-school antibullying programs (Hensums et al, 2022;Yeager et al, 2015) and targeted interventions specifically (Johander et al, 2021) tend to be less effective in adolescence than in childhood. In addition, the intensity of the victimization or bullying (how often it happens, how long it has been taking place) might make interventions less likely to succeed.…”

“…Studies on bullying prevention and intervention have mostly focused on the efficacy of whole-school programs (Gaffney et al, 2019b;Ttofi & Farrington, 2011)-often emphasizing their success, as they lead to lower average levels of bullying perpetration and victimization than "practice as usual." Although researchers have started to tease apart the contributions of different program components from the overall effects (Gaffney et al, 2021a;Hensums et al, 2022), little is known about the effects of targeted interventionsby which we refer to intervening in cases of bullying as they emerge (e.g., discussions with the students involved).…”

Discovering the impact of bullying on adolescents through bibliometric analysis

“…Therefore, if teenagers have positive feelings towards themselves, such as feeling like they have high self-esteem are competent and attractive and get the necessary physical support, teenagers can avoid bullying victimisation that can occur. 57 Friendship quality is an effective factor in preventing peer victimisation, such as high quality friendships. 58 Adolescents who have high levels of support from their friends have lower levels of bullying and victimisation.…”

The Healthy Context Paradox: When Reducing Bullying comes at a Cost to Certain Victims

“…Finally, the effectiveness of different components is likely to depend on the age of the students to whom they are applied (e.g., elementary vs. middle school students) (Yeager et al, 2015). Indeed, some recent meta-analyses have tried to ascertain not only which components are effective, but specifically for whom (Hensums et al, 2022). Even so, it is indisputable that the promotion of bystander intervention is at the core of programs that currently have the greatest effectiveness (e.g., the KiVa program) (Sainio et al, 2020; Salmivalli et al, 2021).…”