I had a cousin who probably could have been diagnosed as a psychopath. He had no sense of right or wrong, of good or bad. The only think that registered with him was who he could manipulate, and whether he could get away with it.

It was interesting to see. At a family funeral, he started goading his brother, talking about how much time he had to golf (in jail, no less) while the brother had to work all the time. He thrived on being an irritant to get his own way.