Reward & Imitation in Social Conformity

Normative social conformity has been proposed to elicit a hedonic reward signal that is dissociable from informational inferences about decision outcomes. If present, such a signal should reinforce not just the decision that preceded it, but also any incidentally co-occurring stimulus features. Alternatively, normative conformity might reflect a non-hedonic imitation algorithm. Across two studies (n=359) we used a non-deceptive multi-participant gambling task in which trial-by-trial information was provided about the selections and monetary payoffs of two other participants facing the same, recurring, options in real time. Consistent with both accounts, and contrary to mere monetary maximization, the probability of staying with a losing option increased with the degree of decision unanimity. However, contrary to the social reward hypothesis, only monetary payoffs modulated the valence of incidental gambling stimuli. A prosocial framing did not significantly alter this pattern of results, which favors an imitative over a hedonic account of normative social conformity.