It's not always straight up immaturity. A lot of it could be other issues related to the bullies environment/household or many other issues.
Classical stereotypical case is that the bully himself has an abusive/alcoholic father. There's a lot of complexity in what's involved here, but society is only equipped to deal with the "immaturity" case which is real but not the only story.
Classical stereotypical case is that the bully himself has an abusive/alcoholic father. There's a lot of complexity in what's involved here, but society is only equipped to deal with the "immaturity" case which is real but not the only story.