Declines in efficacy of anti-bullying programs among older adolescents: Theory and a three-level meta-analysis

Abstract

Highly visible tragedies in high schools thought to involve bullying have directly contributed to public support for state-mandated K-12 anti-bullying programming. But are existing programs actually effective for these older adolescents? This paper first outlines theoretical considerations, including developmental changes in (a) the manifestation of bullying, (b) the underlying causes of bullying, and (c) the efficacy of domain-general behavior-change tactics. This review leads to the prediction of a discontinuity in program efficacy among older adolescents. The paper then reports a novel meta-analysis of studies that administered the same program to multiple age groups and measured levels of bullying (k= 19, with 72 effect sizes). By conducting a hierarchical meta-analysis of the within-study moderation of efficacy by age, more precise estimates of age-related trends were possible. Results were consistent with theory in that whereas bullying appears to be effectively prevented in 7th grade and below, in 8th grade and beyond there is a sharp drop to an average of zero. This finding contradicts past meta-analyses that used between-study tests of moderation. This paper provides a basis for a theory of age-related moderation of program effects that may generalize to other domains. The findings also suggest the more general need for caution when interpreting between-study meta-analytic moderation results.