Psychologists report that people make choices on the basis of "decision utilities'' that routinely overestimate the "experienced utility'' consequences of these choices. This paper argues that this dichotomy between decision and experienced utilities may be the solution to an evolutionary design...

Human groups maintain a high level of sociality despite a low level of relatedness among group members. The behavioral basis of this sociality remains in doubt. This paper reviews the evidence for an empirically identifiable form of prosocial behavior in humans, which we call "strong...