I think that perceived competition plus a feeling of inadequacy breeds bullies.

We have a couple of bullies in my workplace and they will stop at nothing to 'blow their own horn' whenever the 'boss' is around. As a result, they are rewarded by the boss while the unsung heroes remain unnoticed. Yet, it is the quiet, compassionate and supportive workers, who are usually the best at their jobs.

Its the incompetent that need to continually 'promote' themselves and manipulate others to lessen their workload. I see it all the time. The bosses fawn over these assholes because they usually provide some kind of 'volunteer' time while others are doing the real work.

They are masters of manipulation and control. Their fellow workers know it but cannot be 'unprofessional' by calling it to the attention of the boss. The boss interprets this silence as respect for the 'bully'. In fact, if you attempt to expose the asshole, you usually end up making yourself look like a whiner.

Learning to 'stick up for yourself' is a life-long lesson but in the workplace, you have to be very careful that you come across as assertive rather than aggressive. Its a fine line.