Bullying victimization/perpetration in childhood and later adjustment: findings from a 30 year longitudinal study

Purpose This paper aims to report on the associations between reports of bullying victimization and bullying perpetration in childhood and subsequent mental health and adjustment difficulties in late adolescence/adulthood (16‐30 years) in a New Zealand birth cohort. Design/methodology/approach The paper uses data from the Christchurch Health and Development Study, a longitudinal study of a birth cohort of 1,265 individuals born in Christchurch, New Zealand in 1977 and followed to age 30. Findings There were general trends for rates of mental health/adjustment problems to be significantly associated with parental reports of bullying victimization in adolescence, and with parent and teacher reports of bullying perpetration in middle childhood or adolescence. Effect sizes were typically in the small to moderate range, and were reduced by covariate adjustment. After adjustment the majority of associations were statistically non‐significant. Effect sizes did not vary significantly with gender or the age at which outcomes were assessed. Originality/value The paper confirms that reports of bullying perpetration and victimization in childhood were associated with higher rates of later mental health/adjustment problems. Effect sizes were typically in the small to moderate range and, in the majority of cases, were substantially reduced upon covariate adjustment. Effect size estimates were not significantly different between males and females and did not vary with the age at which outcomes were assessed.