Why do adults bully? I can understand somewhat, why children bully and have cliques, I see it as they haven't quite matured, don't know any better, or don't know how to handle social situations etc.

But, why do adults do it? A mature, grown adult? Also, would you say someone who is pompous/arrogant and rude as being a bully, or would that be a seperate character of a person? If you had someone in the workplace who showed this type of behavior to others, and you had the authority to fire them, would you, (after being give a warning?) Even just socializing, would you still want to continue socializing with that person, outside of the workplace? Are they considered a bully?