School Bullies Bully at Home, Too

The study involved 195 children age 10 to 12. Each had a sibling no more than four years older or younger than them. Children were given questionnaires that asked whether they were a victim of bullying, or bullied their peers at school, and whether they were a victim of bullying by a sibling or bullied a sibling at home.

"Children with older male siblings were the most victimized group," said Ersilia Menesini of the Universita’ degli Studi di Firenze, Italy.

Significantly more boys than girls said they bullied their sibling - who was most likely to be younger than them. It’s likely that this form of sibling bullying is all about maintaining a position of dominance, the researchers figure.

"However, for girls, bullying is mainly related to a poor quality of sibling relationship and not to birth order," Menesini said in a statement. "In fact, high levels of conflict and low levels of empathy were significantly related to sibling bullying and sibling victimization."

Children who bullied siblings were likely to bully their peers, while victims at home were likely to also be victimized at school.

"It is not possible to tell from our study which behavior comes first, but it is likely that if children behave in a certain way at home, bullying a sibling for instance, if this behavior goes unchecked they may take this behavior into school," Menesini said.

The behavior doesn't necessarily end with growing up. Other studies have documented significant bullying in the workplace.

The results are detailed online by the British Journal of Developmental Psychology.

• 8 Tactics to Bust the Office Bully
• Study Reveals Widespread Office Bully Problem
• The Evolution of Human Aggression