Experimental comparison of direct, general, and indirect reciprocity

• We report on an experiment comparing three forms of reciprocity.
• Direct and generalized reciprocity are equally intense.
• Intentions do not contribute to reciprocity.
• Social influence does not explain reciprocity.

In this paper, we examine reciprocity in an experiment using a sequential dictator game where the first round recipient becomes the second round dictator. The experiment is designed to study whether reciprocity can be observed when efficiency gains or strategic motivations are not present, i.e. when sending money in the first round is due to certain types of distributional preferences. We ask how second round dictators response to first round dictators’ kind or unkind actions. We separate between three types of reciprocity. Direct reciprocity occurs when the second round dictator responses directly to the first round dictator. A second round dictator shows indirect reciprocity when s/he is aware of the first round play, has not taken part in it, but yet reacts to the first round dictator's action. In generalized reciprocity, the second round dictator has taken part in the first round play but responses to someone else than the first round dictator. Our results show evidence of strong reciprocity in all three cases. Further, in the experiment, direct and generalized reciprocity are equally intense. An unexpected result is that intentions do not seem to play a role in our setting. Further, we found no evidence for social influence affecting individual behaviour.