Imitative Trust versus Indirect Reciprocity

Indirect reciprocity, a key concept in evolutionary game theory, provides a mechanism that allows cooperation to emerge in a population of self-regarding individuals even when repeated interactions between pairs of actors are unlikely. Recent empirical evidence, in particular laboratory experiments, show that humans typically follow complex assessment strategies involving both reciprocity and imitation when making cooperative decisions. However, we currently have no systematic understanding of how indirect reciprocity and imitation mechanisms interact, and how they jointly affect the emergence of cooperation and the allocation of resources. Here we extend existing evolutionary models, which use an image score for reputation to track how individuals cooperate by contributing resources, by introducing a