There is a puzzle about why self-deception, a process that obscures the truth, is so pervasive in human behavior given that tracking the truth seems important for our survival and reproduction. William von Hippel and Robert Trivers argue that, despite appearances, there is good reason to think that self-deception is an adaptation by arguing: self-deception leads to a positive self-perception and a positive self-perception increases an individual’s fitness. D.S. Neil Van Leeuwen, however, gives persuasive arguments against both steps. In response, (...) we will defend both propositions, thereby supporting the conclusion that self-deception indeed has adaptive value. The first premise will be bolstered by a survey of the philosophical literature and empirical work on self-deception, whereas the second will be strengthened by empirical research on a behavioral phenomenon known as the winner effect. (shrink)