title: Knowledge of Social Affiliations Biases Economic Decisions.
abstract: An individual's reputation and group membership can produce automatic judgments and behaviors toward that individual. Whether an individual's social reputation impacts interactions with affiliates has yet to be demonstrated. We tested the hypothesis that during initial encounters with others, existing knowledge of their social network guides behavior toward them. Participants learned reputations (cooperate, defect, or equal mix) for virtual players through an iterated economic game (EG). Then, participants learned one novel friend for each player. The critical question was how participants treated the friends in a single-shot EG after the friend-learning phase. Participants tended to cooperate with friends of cooperators and defect on friends of defectors, indicative of a decision making bias based on memory for social affiliations. Interestingly, participants' explicit predictions of the friends' future behavior showed no such bias. Moreover, the bias to defect on friends of defectors was enhanced when affiliations were learned in a social context; participants who learned to associate novel faces with player faces during reinforcement learning did not show reputation-based bias for associates of defectors during single-shot EG. These data indicate that when faced with risky social decisions, memories of social connections influence behavior implicitly.
authors.affiliation: Department of Psychology, Princeton University, Princeton, NJ, United States of America.
authors.forename: Joel E
authors.initials: JE
authors.lastname: Martinez
authors.affiliation: Department of Psychology, The University of Texas at Austin, Austin, TX, United States of America.|Center for Learning and Memory, The University of Texas at Austin, Austin, TX, United States of America.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Mack
authors.affiliation: Center for Learning and Memory, The University of Texas at Austin, Austin, TX, United States of America.
authors.forename: Bernard D
authors.initials: BD
authors.lastname: Gelman
authors.affiliation: Department of Psychology, The University of Texas at Austin, Austin, TX, United States of America.|Center for Learning and Memory, The University of Texas at Austin, Austin, TX, United States of America.|Department of Neuroscience, The University of Texas at Austin, Austin, TX, United States of America.
authors.forename: Alison R
authors.initials: AR
authors.lastname: Preston
mesh_terms: D000328:Adult; D003657:Decision Making; D005260:Female; D005716:Game Theory; D006801:Humans; D007398:Interpersonal Relations; D019359:Knowledge; D007858:Learning; D008297:Male; D008568:Memory; D016017:Odds Ratio; D055815:Young Adult