Reward and Imitation in Social Conformity.

PURPOSE: 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 incidental, contextual, and stimulus features. Here, we pit this account against a non-hedonic imitation algorithm.

METHOD: Across two studies (n = 359), we used a nondeceptive three-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. We use computational cognitive modeling to assess the relative contributions of monetary reward, social reward, and non-hedonic imitation to norm alignment.

FINDINGS: Consistent with both social reward and imitation accounts, but 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 hybrid weighted sum of the two models failed to improve on imitation performance, and a prosocial framing did not significantly alter the pattern of results.

CONCLUSIONS

Our findings suggest a prominent role for non-valanced imitative processes in normative conformity. Future work will address how social and informational constraints shape the roles of imitation and reward in social conformity and observational learning.