Cross-national consistency in the relationship between bullying behaviors and psychosocial adjustment.

OBJECTIVE To determine whether the relationship between bullying and psychosocial adjustment is consistent across countries by standard measures and methods. DESIGN Cross-sectional self-report surveys were obtained from nationally representative samples of students in 25 countries. Involvement in bullying, as bully, victim, or both bully and victim, was assessed. SETTING Surveys were conducted at public and private schools throughout the participating countries. PARTICIPANTS Participants included all consenting students in sampled classrooms, for a total of 113 200 students at average ages of 11.5, 13.5, and 15.5 years. MAIN OUTCOME MEASURES Psychosocial adjustment dimensions assessed included health problems, emotional adjustment, school adjustment, relationships with classmates, alcohol use, and weapon carrying. RESULTS Involvement in bullying varied dramatically across countries, ranging from 9% to 54% of youth. However, across all countries, involvement in bullying was associated with poorer psychosocial adjustment (P<.05). In all or nearly all countries, bullies, victims, and bully-victims reported greater health problems and poorer emotional and social adjustment. Victims and bully-victims consistently reported poorer relationships with classmates, whereas bullies and bully-victims reported greater alcohol use and weapon carrying. CONCLUSIONS The association of bullying with poorer psychosocial adjustment is remarkably similar across countries. Bullying is a critical issue for the health of youth internationally.