As Ochberg implies, psychopaths don't have ethical considerations, and narcissists and asocial personalities don't care.
In layman's terms I think most of these fellows have a great hole in their being. They know that something is not right with them, but their egos will not allow them to acknowledge it.
Those who gravitate toward the corporate power structures can be quite successful in some organizations. But despite outward success they are always restless, unfulfilled, and tend to project their dissatisfaction outward and ascribe it to others. If they succeed it is all them, but if they fail, someone else is at fault.
They are incapable of trust, because everything they do is a facade, a lie. Therefore they rarely have a real relationship with their families, and at best view them as a desirable addition to their collection. They have utter contempt for other people, although they will use flattery and other means to create a dependency while they are using them. And after that is done, they will be discarded without another thought.
They are like sharks, endlessly seeking to fill their terrible emptiness with possessions, be they things or other people. They are literally insatiable in their needs, and highly focused in their pursuit of them.
They are very clever in finding the weaknesses in people and organizations, and will exploit them ruthlessly. Ethics and conscience provide no brake or boundaries on their willingness to say and do anything that is required to achieve their ends. If you attempt to thwart, be prepared for something a little different, and completely off the hook in response.
It is really something to see them at work. The destruction they can wreak, sometimes with remarkably superficial charm and high verbal acuity, is hard to describe until you see it in action.
They are always a challenge to the HR and compliance departments, and frequently end up badly, one way or the other. It becomes a personal challenge to see how far one can go without being stopped, far beyond any personal needs or requirements. Flouting the rules becomes a game in itself.