Trust, Reciprocity, and Social History

We designed an experiment to study trust and reciprocity in an investment setting. This design controls for alternative explanations of behavior including repeat game reputation effects, contractual precommitments, and punishment threats. Observed decisions suggest that reciprocity exists as a basic element of human behavior and that this is accounted for in the trust extended to an anonymous counterpart. A second treatment, social history, identifies conditions which strengthen the relationship between trust and reciprocity.