UC Irvine

Consensus seeking – abandoning one’s own judgment to align with a group majority – is a fundamental feature of human social interaction. Notably, such striving for majority affiliation often occurs in the absence of any apparent economic or social gain, suggesting that achieving consensus might have intrinsic value. The current work assessed the expression and transfer of valence associated with social conformity, and the relation between conformity and exploratory behavior. In the first two studies, using a paradigm in which participants assumed the role of a juror evaluating a series of misdemeanor criminal cases, we found that contexts that had been repeatedly paired with consensus decisions were rated as more likable, and selected more frequently in a two-alternative forced choice test, than were contexts paired with dissent from a unanimous majority. The second of these studies ruled out inferences about the accuracy of the majority opinion as the basis for such evaluative changes. A subsequent set of studies employed a simple gambling task, in which the decisions of ostensible previous gamblers were indicated below available options on each trial, to assess the trade-off between social and non-social currencies and the transfer of social valence to interpersonal stimuli. In spite of demonstrating near-perfect knowledge of objective reward probabilities, participants reliably preferred gambling options and previous gamblers associated with conformity over those associated with reward. Formally, we found that a reinforcement learner that treated conformity as a surrogate reward provided a better account of choice preferences than did a conventional model. Finally, we investigated the relationship between social conformity and a tendency to explore the environment for potentially greater, yet unknown, rewards. We found that the degree to which participants adjusted their ratings of subjective food preferences to match the aggregate ratings of ostensible previous participants was negatively correlated with exploratory behavior in a multi-armed bandit task. In summary, we provide evidence for a common value-scale for social and non-social currencies, an ability of conforming decisions to imbue concomitant stimuli with affective significance, and a negative relationship between social conformity and reward exploration. By characterizing conformity as reinforcement learning, the framework advanced in this dissertation provides a mechanism for how apparently inconsequential consensus decisions may be motivated by previously acquired valence, as well as for how that valence may in turn be transferred to concomitant stimuli, both contextual and interpersonal. This novel approach will bridge a critical gap, at neural and behavioral levels, between complex socio-cognitive representations and basic mechanisms of reward-based learning and decision-making.