I study a two-period model of conflict with two combatants and a third party who is an ally of one of the combatants. The third party is fully informed about the type of her ally but not about the type of her ally's enemy. There is a signaling game between the third party and her ally's enemy...

Repeated interactions provide a prominent but paradoxical hypothesis for human cooperation in one-shot interactions. Intergroup competitions provide a different hypothesis that is intuitively appealing but heterodox. We show that neither mechanism reliably supports the evolution of cooperation...

Does the cultural background influence the success with which genetically unrelated individuals cooperate in social dilemma situations? In this paper we provide an answer by analyzing the data of Herrmann et al. (Science 2008, pp. 1362-1367), who study cooperation and punishment in sixteen...

When the repeated prisoner's dilemma setup is generalized to allow for a unilateral breakup, maximal efficiency in equilibrium remains an open question. With restrictions of simple symmetry with eternal mutual cooperation, defection, or (matched) alternation on the equilibrium path, we describe...

In some important multi-player situations, such as efforts to supply a global public good, players can choose the game they want to play. In this paper we conduct an experimental test of the decision to choose between a “tipping” game, in which every player wants to contribute to the public...

We analyze cooperation within a company setting in order to study the relationship between cooperative attitudes and financial as well as non-financial rewards. In total, 910 employees of a large software company participate in an incentivized online experiment. We observe high levels of...

We study the development of cooperation in 929 young children, aged 3 to 6. In a unified experimental framework, we examine pre-registered hypotheses about which of three fundamental pillars of human cooperation – direct and indirect reciprocity, and third-party punishment – emerges earliest...

Understanding the roots of human cooperation among strangers is of great importance for solving pressing social dilemmas and maintening public goods in human societies. We study the development of cooperation in 929 young children, aged 3 to 6. In a unified experimental framework, we examine...