Defying Hammurabi: Is Reciprocity Driven Exclusively by Internal Motives?

Observed unselfish behavior in experimental settings has been suggested as evidence that people’s generosity is driven by social preferences. However, a pivotal body of literature has shown that altruistic giving declines... [ view full abstract ]

Observed unselfish behavior in experimental settings has been suggested as evidence that people’s generosity is driven by social preferences. However, a pivotal body of literature has shown that altruistic giving declines when people are provided with excuses for self-interest. DellaVigna et al. (2012) find that fewer homeowners contribute to door-to-door fundraisers when they are informed in advance about the exact time of solicitation. This occurs because, knowing exactly when the fundraiser will take place, people can deliberately avoid being asked to donate money to charity. This observation suggests that a person’s altruism may not be entirely motivated by a genuine concern for pro-social outcomes but rather by external motives such as social pressure, image concerns, and social norms. The finding that altruistic giving is not exclusively the product of true social preferences has been reproduced numerous times. Yet, little is known about the drivers of other types of pro-social behavior, such as reciprocity. To this end, I conducted an experiment where subjects were provided with excuses to justify selfishness in an environment enabling reciprocal behavior. The experiment allowed me to observe whether the incidence of reciprocity is driven exclusively by internal motives.