The observability of partners' past play is known to theoretically improve cooperation in an infinitely repeated prisoner's dilemma game under random matching. This paper presents evidence from an incentivized experiment that reputational information per se may not improve cooperation. A...

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...