The researchers also checked to see if the variation among the groups could be attributed to differences in socio-economic status, or family dysfunction/instability, or maltreatment (which they defined as physical or sexual abuse). All three groups — the victims, the bullies, and the bully-victims — had higher rates of some type of family hardship than the kids who didn't experience bullying at all. For the victims, the risk of anxiety disorders remained strong even when taking into account family problems, though the risk of depression did not (it dropped just below statistical significance if the victims came from a stable home, Copeland said). For bully-victims, the risk of both anxiety and depression held, and for bullies, the risk of antisocial personality disorder did as well. In other words, these results suggest that bullying scars people whether they grow up in a home with two functional parents or with frequent arguing, not much parental supervision, divorce, separation or downright abuse or neglect. It's a finding that's in line with other work, for example by Judith Rich Harris, who in her book "The Nurture Assumption," shows that kids are very much influenced and affected by their peers.
Why does bullying have such far-reaching impact? Copeland and his team suggest the experience may change kids' physiological response to stress, and their ability to cope. This looked especially stark for the bully-victims. "It was definitely the case that chronic bullying led to worse outcomes, but much more the case that being a bully-victim was associated with really significant problems," Copeland said. The biggest cry for help is coming from that group. Fortunately, it's a smaller number than victims overall." Bully-victims, Copeland and others have found, have more problems at home and the most trouble with impulse control and aggression. Sometimes they do the dirty work for popular kids who bully to curry favor with them. "I don't think things are working out socially for them in a lot of ways," Copeland said.