I heard on the local news the other night that a study has been done in Finland on the long-term effects of bullying for both the person being bullied and the bully. The data matches my assumptions about how bullying effects both groups. In the article I found it says:
Head Researcher Andre Sourander from the Department of Child Psychiatry at the University of Turku said that severe bullying and victimization have clear connections to psychiatric problems and crime committed later in life. Both boys who are bullied and the bullies themselves commit one-third of the crimes carried out by youth in Finland…
Children who were victims of severe bullying were more likely to suffer from anxiety and depression than their peers. Meanwhile, children who were bullies were more likely to develop personality disorders.
If you want to read the full study, which is fascinating, click here!