Objective: To study correlations of childhood bullying and victimization with juvenile criminality.
Design: Longitudinal birth cohort study from age 8 years to ages 16 to 20 years.
Setting: Population-based study from Finland.
Participants: The sample comprised 2551 boys (86.6% of the original birth cohort) with complete information about bullying and victimization from parents, teachers, and children at age 8 years.
Main outcome measure: Information about criminal offenses from the National Police Register at ages 16 to 20 years.
Results: Frequent bullies and those who frequently both bullied and were bullied (8.8% of the sample) were responsible for 33.0% of all juvenile crimes during the 4-year study period. Frequent bully-only status predicted both occasional and repeated offending, whereas bully-victim status predicted repeated offending. Bullying predicted most types of crime (violence, property, drunk driving, and traffic offenses) when controlled with parental education level. However, frequent bullies or victims without a high level of psychiatric symptoms were not at an elevated risk for later criminality.
Conclusions: Boys who frequently bully are at risk for later criminality when this condition is accompanied by a high level of psychiatric symptoms. Frequent bullies should be actively screened for psychiatric problems.