I have noticed that some power-mad people tend to have a certain demeanor closely related to nervousness. The ones I have observed also likely correctly perceive a lack of respect for them due to their being stupid, uneducated, or at the bottom of the pecking order. This is probably a product of their self-centeredness of their concerns and their self-identity as powerful in a group.

These people are capable of functioning in organizations at the lowest level but when they gain power, they tend to abuse their subordinates not for their subordinates mistakes but for their own failings as a "pick-me-up". They get annoyed when people don't make mistakes that they can jump on as a justification. The result is never good for organizational cohesion and morale.

It is understanding those who cannot handle power that is one of the more important lessons when coming up from the bottom. The general idea can be grasped with accounts of other people's life under such people but the lessons are far more firmly grasped when you yourself are under their thumb absolutely powerless.