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

匿名的慷慨行为在日常生活中很普遍：人们献血，停下来帮助一个被困的司机，写匿名的在线评论，或者为开源软件贡献代码，通常没有任何直接的奖励或认可。这个难题的一个重要关键可能是帮助行为可以传染的可能性--对接受或观察到的帮助做出反应的帮助有可能引发一系列远远超出最初行为的慷慨行为。桥接两个大的，但在很大程度上断开现有的文献-利他行为和社会传染-本论文项目确定了两种机制，改变的概率，以帮助一个陌生人：广义互惠（帮助的接受者可能会支付它前进）和第三方模仿（帮助给予的观察者可能会模仿它）。这些机制被假设为不同的影响行为：虽然多次接受陌生人的帮助会增加帮助陌生人的概率，但观察陌生人之间的帮助会先增加然后减少这种概率;然而，对于那些接受过帮助的人来说，后者的减少会更小。因此，当第三方模仿与广义互惠相互作用时，慷慨的级联预计会更频繁，但到达的人更少。为了测试的有效性和鲁棒性的宏观影响和实证相关性的假设机制，提出了两项研究：一个模拟实验与基于代理的模型和一个在线实验与人类subjects.Broader ImpactsThe项目将推进理论知识的帮助行为和它的扩散和在线行为实验的方法。此外，慷慨的潜在涟漪效应意味着，当我们帮助他人时，我们也可能间接地帮助下游更多的人。更好地了解可能引发这些级联的机制，有可能通过更有效地针对过去受益者，为调动自愿捐款和亲社会行为的努力提供信息。特别是，可以利用普遍互惠和第三方模仿来加强大规模在线协作项目和用户生成内容社区的创造性参与和社区形成。

Michael MacyMilena TsvetkovaCornell UniversityAnonymous 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 ImpactsThe 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.