Biological, cognitive, and learning explanations of altruism, selfishness, and self-control can be integrated in terms of adaptive strategies. The key to understanding why humans and other animals sometimes resist temptation and sacrifice their immediate interests for the sake of others lies in mapping the design of the evolved mental mechanisms that give rise to the decisions in question.

McKay & Dennett (M&D) have done an admirable job of distinguishing among various forms of misbelief and evaluating the idea that they stem from evolved mental mechanisms. We argue that a complete account of misbeliefs must attend to the role that others play in creating and maintaining positive illusions.