While there may be the occasional child with the future diagnosis of antisocial personality disorder (what we commonly call sociopaths), most young bullies are troubled children who need help. Some are themselves abused, others are simply insecure and don't have the positive social and coping skills to deal with that in a more productive way. Both victim and bully need intervention.
Jodee Blanco, a former bullied student who now gives seminars and presentations to schools says in her promotional material: "After the student presentation(s), I make myself available to do one-on-one sessions with any students who wish to speak with me. Typically, those students will include victims who want a sympathetic ear and “elite tormentors” who never realized they were cruel until they heard my talk, and now want my advice on how to make amends to their victims."
There's a third category: the bystander. These are the children who feel too scared to confront the bully and in some cases are tormented by their inaction. Some school programs have worked not only with bullies and victims, but with the other students to empower them with the verbal skills to intervene as a group as well as seek adult assistance. This has worked very well in the schools who have utilized non-violent communication programs that teach these skills. Bullying incidents decline sharply and victims feel the support and concern of other students while bullies know that no one is impressed with their behavior and that this does not make them look powerful to other students. Behavior that is not rewarded tends to stop. :)