Cognitive Science Seminar

Leor Hackel, Postdoc Student with Jamil Zaki, Psychology, Stanford University

Instrumental learning in social interaction

We learn about people through positive and negative interactions with them. These experiences help us decide whether to approach others again in the future. Yet, traditional approaches to social cognition focus on more passive forms of learning ("person perception"), in which perceivers see descriptions of another person’s behavior. I will describe a program of research testing how we learn about people by making interaction choices and experiencing outcomes—or instrumental social learning. Through behavioral experiments, computational modeling, and fMRI, this work demonstrates that people gravitate towards partners who provide rewarding outcomes (e.g., an expensive gift) and partners who display valuable social traits (e.g., generosity). Both types of learning involve ventral striatum—a region strongly linked to reinforcement—while trait learning further recruits regions associated with social impression updating. Moreover, both forms of learning give rise to reciprocity: in economic games, people reciprocate kindness not only based on the generosity others display, but also based on the rewards others have provided. As a result, people reciprocate more with "wealthy" individuals, propagating economic inequality. This work provides a psychological and neural model describing how we learn the value of different social interactions, and highlights novel implications for social behavior.