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...

To fully understand the motives for delegating a decision right, it is important to study responsibility attributions for outcomes of delegated decisions. We conducted laboratory experiments in which subjects could either choose a fair allocation or an unfair allocation or delegate the choice,...