Not selfishness, but precisely the absence of a self. Look at them. The man who cheats and lies, but preserves a respectable front. He knows himself to be dishonest, but others think he's honest and he derives his self-respect from that, second-hand. The man who takes credit for an achievement which is not his own. He knows himself to be mediocre, but he's great in the eyes of others.
For the New Intellectual: The Philosophy of Ayn Rand (50th Anniversary Edition) (ed. Penguin, 1963) - ISBN: 9781101137680