Dissertation Research: Generalized Reciprocity: Understanding the Social Contagion of Altruistic Behavior

Cornell University, Ithaca NY

Investigators

Abstract

Michael Macy Milena Tsvetkova Cornell University Anonymous acts of generosity are widespread in daily life: people donate blood, stop to help a stranded motorist, write anonymous online reviews, or contribute code to open-source software, often without any direct reward or recognition. An important key to this puzzle may be the possibility that helping behavior can be contagious -- helping in response to receiving or observing help has the potential to trigger a chain of generosity that reaches far beyond the original act. . Bridging two large but largely disconnected existing literatures -- on altruistic behavior and social contagion -- this dissertation project identifies two mechanisms that alter the probability to help a stranger: generalized reciprocity (a recipient of help is likely to pay it forward) and third party imitation (an observer of help giving is likely to emulate it). These mechanisms are hypothesized to affect behavior differently: while receiving help from strangers multiple times will increase the probability to help a stranger, observing help between strangers will initially increase and then decrease that probability; this latter decrease, however, will be smaller for those who have received help. As a result, when third-party imitation interacts with generalized reciprocity, cascades of generosity are expected to be more frequent but reach fewer people. To test the validity and robustness of the macro-implications and the empirical relevance of the hypothesized mechanisms, two studies are proposed: a simulation experiment with an agent-based model and an online experiment with human subjects. Broader Impacts The project will advance theoretical knowledge about helping behavior and its diffusion and methodologies for online behavioral experiments. In addition, the potential ripple effect of generosity means that when we help others, we may also be indirectly helping many more people downstream. Better understanding of the mechanisms that can trigger these cascades has the potential to inform efforts to mobilize voluntary contributions and pro-social behavior by more effectively targeting those who have benefited in the past. In particular, generalized reciprocity and third-party imitation can be harnessed to enhance creative participation and community formation in large-scale online collaborative projects and user-generated-content communities.