In this study we propose a formal framework for the indirect evolutionary approach as initiated by Güth and Yaari (1992). It allows to endogenize preferences and to study their evolution. We define two-player indirect evolutionary games with observable types and show how to incorporate...

Economists have a long tradition in identifying the evolution of cooperation in large, unstructured societies as a puzzle. We suggest a new explanation for cooperation which avoids restrictions of most previous attempts. Our explanation deals with the role of internalized norms for cooperation...

Relatedness and synergy affect the selection pressure on cooperation and altruism. Although early work investigated the effect of these factors independently of each other, recent efforts have been aimed at exploring their interplay. Here, we contribute to this ongoing synthesis in two distinct...