There may be some supporting evidence in book I read recently, "Wisdom ot the Psychopaths".

Wealth (and power) are apparently easier to accumulate if you do not suffer from unwanted emotional responses. The book lists several examples, and provides a number of potential reasons. I can dig the book out later today and find some proper sections to quote, if needed.

Interestingly enough, the author uses the term psychopath in context I have usually associated with sociopathy.