Why do people engage in costly cooperation with unknown others that they will never meet again? Answers to this evolutionary puzzle emphasize the role of indirect reciprocity (i.e., cooperation through reputation), whereby cooperation is not reciprocated by the recipient but by other members of...

Experimental studies show that the Nash equilibrium and its refinements are poor predictors of behavior in non-cooperative strategic games. Cooperation models, such as ERC and inequality aversion, yield superior predictions compared to the standard game theory predictions. However, those models...

What determines people's moral judgments of selfish behaviors? Here we study whether people's normative views in trust and gift exchange games, which underlie many situations of economic and social significance, are themselves functions of positive emotions. We used experimental survey methods...