Those who receive help may be more likely to help a third party. This pay-it-forward behavior, called generalized reciprocity, can be powerful in spreading kindness from person to person. We use laboratory games to explore the psychological motivations that contribute to generalized reciprocity....

This paper provides an evolutionary justification for overconfidence. Players are pairwise matched to compete for a resource, and there is uncertainty about who will win the resource if they choose to compete. Players have different confidence levels about their chance of winning, although in...