Behavioral Social Neuroscience Seminar

Trust is critical to human social relationships, but opens the door to exploitation. How can we tell who to trust? And how do people honestly advertise their trustworthiness to others? In this talk, I will address this question by focusing on two case studies: third-party punishment and uncalculating cooperation. People ubiquitously condemn and punish a ride range of immoral and selfish behaviors, even as unaffected observers. And it is common to sacrifice to help others without carefully calculating the costs and benefits of doing so, despite the risk of giving too much. I will present evidence from economic game experiments that one reason people engage in these costly behaviors is to advertise their trustworthiness to observers. We show that in contexts where these behaviors are more likely to elicit trust from observers, subjects are more likely to (i) pay to punish selfishness, and (ii) decide whether to cooperate without choosing to learn the personal cost of doing so. Moreover, punishment and uncalculating cooperation are perceived as, and actually are, honest and reliable signals of trustworthiness. Together, these experiments reveal how the drive to appear trustworthy shapes two key signatures of human morality: moralistic punishment and uncalculating cooperation.