We study conflict between two groups of individuals. Using Schaffer's (1988) concept of evolutionary stability we provide an evolutionary underpinning for in-group altruism combined with spiteful behavior towards members of the rival out-group. We characterize the set of evolutionarily stable...

This paper analyses preference evolution in a bargaining situation. We show <p> that preferences for reciprocity, that sustain a conflict-free outcome, are viable <p> if players have enough information about opponents’ preferences. However, depending <p> on the initial starting point, preference...</p></p></p>