According to information given in the article, almost 30 percent of American children ages 11 to 16 years report involvement in bullying behavior as the bully, the target, or both. The authors define bullying behavior as one that involves a difference in power between the bully and the target and carries an intention to harm. The abusive nature of bullying and the lack of regard for others may be an important risk factor for involvement in more serious violent behaviors in the future.

Tonja R. Nansel, Ph.D., and her American colleagues investigated possible connections between a history of being a bully or a target of one and risk for future violent behavior. They analyzed data from 15,686 U.S. school children who completed the World Health Organization's Health Behavior in School-Aged Children survey in 1998. The survey asked children whether they ever carried a weapon such as a gun, knife, or club for self defense, whether there was any history of fighting, and whether they had ever been injured in a fight.

The researchers found that involvement in any violence-related behavior ranged from 13 to 23 percent for boys and 4 to 11 percent for girls. Bullying or being bullied was related to violent behavior among both boys and girls. The risk of engaging in violent behavior was higher in those who described themselves as bullies than it was for children who reported being the target of a bully. The risk was even greater if bullying behaviors took place away from school.

For example, the relative risk of carrying weapons for self defense was 1.5 for children who reported being bullied at school and 2.6 for children who acted as bullies at school. Risk rose when bullying behaviors occurred at places other than school: The risk of carrying weapons in self defense was 4.1 for bullies and 5.9 for children who were the bullies’ targets.

"In this study, a strong and consistent relationship between bullying and involvement in violent behaviors was observed," wrote the authors. "This suggests that bullying is likely to occur concurrently with more serious aggressive behavior, and while prevalent, should not be considered a normative aspect of youth development."