Background
Peer victimisation is common and predicts increased internalizing symptoms. Low self-esteem, which is associated with both greater peer victimisation and higher internalizing problems, may help explain why victimised adolescents experience greater internalizing symptoms. Objectives of the present research were to establish the relationships between peer victimisation, internalizing problems, and self-esteem, and to test whether self-esteem mediates the effect of victimisation on internalizing symptoms.
Methods
We conducted a systematic literature search in Psychinfo, ERIC, Web of science, and Pubmed, following PRISMA guidelines. Inclusion criteria were: age 10–18 years; empirical studies that measured a) internalizing symptoms, b) self-esteem, and c) peer victimisation or bullying; design was either longitudinal or cross-sectional with a comparison group. Quality assessment were conducted using the Newcastle–Ottawa Quality Assessment Scale. We conducted random effects models and a meta-mediation analysis, with self-esteem acting as a mediator between peer victimization and internalizing symptoms.
Results
Sixteen papers with a total of N = 35,032 (53% female) participants met the criteria for inclusion in the meta-analysis. The meta-analysis demonstrated an association between peer victimisation and both high internalizing problems (r = .31, CI 95 = .26 to.36) and low self-esteem (r = -.25, CI 95 = -.29; to -.22), and between low self-esteem and high internalizing problems ((r = -.38, CI 95 = -.42 to -.33), as well as an indirect effect of peer victimization on internalizing symptoms via self-esteem (ß = .10, CI lower = .07, CI upper = .13).
Conclusions
Peer victimization, high internalizing symptoms and low self-esteem are all mutually related. Peer victimization partially mediates internalizing symptoms via self-esteem. Anti-bullying programmes may consider incorporating self-esteem building exercises in bully-victims. Limitations include high heterogeneity of results.