Psychology behind people that abuse their power?

[whoiam]

People with power and positive reputations have been known to sometimes have flare ups in their temper. By this, I'm not talking of the normal occasional "don't feel like talking" that happens here and now. But sometimes taking penalties of someone of a lower position e.g. boss on cubicle worker in withdrawing health benefits, to extremes. Then later taking great measures to report a person with faulty accounts (i.e. making up stories).

What have been common etiologies for such occasions? Personal life stresses? Subsequent instinctive defensiveness when realizing they were in the wrong and fearing their reputation? Drugs?

Especially, is there any kind of psychological theory behind it? e.g. upbringing of sense of inferiority and/or potential abuse formulating defensive semi-hostile flare ups?
I meant to say *some* people have experienced flare ups. There are definitely people in power that do a lot of good in society.