title: Reputation Effects in Public and Private Interactions.
abstract: We study the evolution of cooperation in a model of indirect reciprocity where people interact in public and private situations. Public interactions have a high chance to be observed by others and always affect reputation. Private interactions have a lower chance to be observed and only occasionally affect reputation. We explore all second order social norms and study conditions for evolutionary stability of action rules. We observe the competition between "honest" and "hypocritical" strategies. The former cooperate both in public and in private. The later cooperate in public, where many others are watching, but try to get away with defection in private situations. The hypocritical idea is that in private situations it does not pay-off to cooperate, because there is a good chance that nobody will notice it. We find simple and intuitive conditions for the evolution of honest strategies.
authors.affiliation: Department of Evolutionary Studies of Biosystems, School of Advanced Sciences, SOKENDAI (The Graduate University for Advanced Studies), Hayama, Kanagawa, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ohtsuki
authors.affiliation: Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Iwasa
authors.affiliation: Program for Evolutionary Dynamics, Harvard University, Cambridge, Massachusetts, United States of America.|Department of Mathematics, Harvard University, Cambridge, Massachusetts, United States of America.|Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Nowak
mesh_terms: D019295:Computational Biology; D003299:Cooperative Behavior; D006801:Humans; D007398:Interpersonal Relations; D008960:Models, Psychological; D019370:Observation; D018907:Privacy