Self-interested learning is more important than fair-minded conditional cooperation in public-goods games

Abstract Why does human cooperation often unravel in economic experiments despite a promising start? Previous studies have interpreted the decline as reaction of disappointed altruists retaliating response to non-altruists (Conditional Cooperators hypothesis). This interpretation has been considered evidence uniquely form cooperation, motivated by an altruistic concern for equality (‘fairness’) and requiring special evolutionary explanations. However, typically shown individuals not only information about decisions their groupmates (social information) but also own payoffs. Showing both confounds explanations based on conditional with confused learning how better play game (Confused Learners Here we experimentally decouple these two forms information, thus hypotheses, repeated public-goods game. Analysing 616 Swiss university participants, find that payoff leads greater decline, supporting Confused hypothesis. In contrast, social small or negligible effect, contradicting Conditional We widespread confusion selfish motives, suggesting is maybe so unique after all.