I'd say it's much more willingness to be a bit psychopathic. Most people wouldn't compromise their integrity to move into the C-suite. The competition is fierce, so the people who make it to the top are the people who /are/ willing to do anything to move into the C-suite.

I've also done work at that level, and some people outwardly appeared as sleazeballs, some almost radiated charisma and integrity, but when you got down to it, at the organization i was at, all were evil, backstabbing bastards.

Middle managers saw a lot of that, but tended to be decent people. And line employees never saw that -- middle management shielded them.

Good books to understand these dynamics better:

* Dictator's Handbook.

* Power, by Pfeffer.

Disclaimer, since I got jumped on this before: This refers to big organizations. If you're the CEO of a 5-person startup, this doesn't apply to you.