Successful deception is facilitated by self-deception. So, if you really believe in X, then you're going to be a more successful salesman to convince other people of X. So, if you believe you're, let's say, a 10 in mate value, and you truly believe it, even if you're not, I'm going to have a more successful time convincing you that I am as well. And so, the hypothesis is basically that people self-deceive in order to increase the effectiveness of actual deception.