Self-deception has done us proud. Without it ... we might still be running naked through the forest. ... Self-deception was a splendid adaptation in a world populated by nomadic bands armed with sticks and stones (Smith, 2004) [...] admittedly, bias and self-deception do produce many personal and social benefits. For example, by over-estimating our ability we not only attract social allies, we also raise our self-esteem and happiness (Taylor, 1989), and motivate ourselves to excel (Kitcher, 1990) [...]

• http://hanson.gmu.edu/moretrue.pdf