It has been suggested by some that psychopathy may in fact be an evolutionary adaptation. I first read of this theory in
Steven Pinker's very excellent
The Blank Slate: the Modern Denial of Human Nature.
In that node, deep thought explains how those afflicted with antisocial personality disorder view the world in a qualitatively different manner than the rest of us. Indeed, they likely view it the same way an evolutionary psychologist might: a vast social contract kept alive by our innate altruism.
While altruism is of course an admirable personality trait, few of us excercise it by choice. Out of context, it is blatantly maladaptive. However, when exercised by an entire species, it works to the betterment of all, since we can be relatively confident that our favors and kind gestures will be repaid. As a result, our tendencies towards generosity and reciprocal social ties have become genetically ingrained.
Enter psychopathy. It has been mentioned in related nodes that people with this condition tend to be extremely charismatic, persuasive, and intelligent. These are not qualities that generally accompany mental disorders. While an entire society of acute sociopaths would fall apart, a genetic combination that favored intelligence and charisma along with a total lack of empathy or remorse could be extremely adaptive if it only showed up in every thousandth or millionth individual.
Psychopaths are known to consider members of normal society as mere sheep. While they themselves may be free of the 'shackles' of normal social interation, it isn't by any effort of their own. Morality doesn't really enter into it at all.