Related Experiment Video
Updated: Mar 8, 2026

Chronic Social Defeat Stress in Early Adolescent Male Mice
Published on: January 24, 2025
Bullying and Victimization: The Effect of Close Companionship
Sabine A M Veldkamp1, Elsje van Bergen1, Eveline L de Zeeuw1
1Department of Biological Psychology,Vrije Universiteit Amsterdam,Amsterdam,the Netherlands.
Abstract:
Peer bullying and victimization are a widespread phenomenon among school-age children and can have detrimental effects on the development of children. To examine whether having a close companion during childhood increases or decreases risk of victimization and bullying, this study compared twins to singleton children. A large group of twins (n = 9,909) were included who were compared to their related non-twin siblings (n = 1,534) aged 7-12 from the Netherlands Twin Register, thus creating optimal matching between twins and non-twins. Bullying and victimization were each based on a four-item scale filled out by their teachers. Prevalence rates for either bullying or victimization did not differ between twins and singletons. In total, in the past couple of months, 36% of children bullied peers moderately to severely, and 35% suffered moderately to severely from victimization. Boys were more likely to bully and were more prone to becoming a victim than girls. The most notable finding is that female twin pairs placed together in the same classroom did not bully more often, but were victimized less often, thus pointing to a protective effect of having a close companion in the classroom.
Related Concept Videos
Bullying
Influence of Parents and Peers on Identity
Parental Influence on Identity Development
Parents serve as primary guides and managers in an adolescent's life, offering support instrumental in decision-making and personal growth....
Bystander Effect
Social Facilitation
Friendships and Close Friendships
Relationship with Other Adult Family Members and Siblings

