School Bullying as a Predictor of Violence Later in Life: A Systematic Review and Meta-Analysis of Prospective Longitudinal Studies

• NCJ Number: 240346
• Journal: Aggression and Violent Behavior Volume: 17 Issue: 5 Dated: September/October 2012 Pages: 405-418
• Author(s): Maria M. Ttofi; David P. Farrington; Friedrich Losel
• Date Published: October 2012
• Length: 14 pages
• Publication Format: Article
• Publication Type: Research (Applied/Empirical)
• Language: English
• Country: Netherlands

Annotation

This study examined the relationship between school bullying and aggressive or violent behavior later in life.

Abstract

This paper presents results from a thorough systematic review on the efficacy of school bullying (perpetration and victimization) in predicting aggression and violence later in life. Results are based on prospective longitudinal studies. Two meta-analyses are presented examining whether: a) school bullying (perpetration and victimization) is a significant predictor of later aggression and violence, and b) whether each effect remains significant after controlling for other major childhood risk factors which were significantly related to both the predictors and the outcomes. Results are based on extensive searches of the literature. Nineteen electronic databases and 63 journals were searched from the inception of each database or journal through the end of March, 2012. Bullying perpetration at school was a significant predictor of violence (Adjusted OR = 2.04; 95 percent CI: 1.69-2.45) an average of 6 years later in life. This value of OR means that bullying perpetration increased the risk of later violence by about two-thirds. The summary effect size for bullying victimization versus violence was markedly smaller but still highly significant (Adjusted OR = 1.42; 95 percent CI: 1.25-1.62). This value of OR means that victimization increased the risk of later violence by about one-third. Analyses are presented of various potential moderators (such as the number of risk factors controlled for and the length of the follow-up period) in an attempt to explain the significant heterogeneity in effect sizes. Sensitivity analyses are performed on both meta-analyses, and they indicate that overall there is no evidence of publication bias. The overall findings favor the existence of a more general long-term underlying antisocial tendency rather than a more specific underlying violent tendency. Implications of our research for policy and practice are highlighted and future needs in this area of research are indicated. (Published Abstract)