The effect of self and other social status in behavior and neural responses during Ultimatum Game

MOLA D; BARTFELD P; IBAÑEZ A; GODOY JC; REYNA CE

Workshop; SECOND LATIN-AMERICAN WORKSHOP ON EXPERIMENTAL AND BEHAVIOURAL SOCIAL SCIENCES (LAWEBESS); 2018

Social hierarchies exist in most species, and they are an organizing principle of social groups. Hierarchy refers to the classification of individuals according to multiple aspects, such as social status. Social status refers to an individual's standing in the hierarchy and the honor or prestige associated with that standing. Status provides information to guide decisions affecting the distribution of resources. Previous studies showed that economics resources are distributed unequally depending to the status of people. For example, when people were in a high status experimental condition they rejected more unfair offers in the Ultimatum Game (UG) than when they were in a low social status condition. However, others researchers observed that this effect is no statistically significant when other status is considering. Thus, the way in which one?s own social status interacts with another?s status to influence economic decisions is far from clear, as are the neural processes underlying these decisions. In this study we evaluated the effects of self and other social status on behavior and neural responses among thirty-one students from Córdoba (Argentina). Experiment consisted of two sessions. In the first session the participants completed cube task and they obtained an own status based on his/her performance. In the second session they played of the UG as respondent and they received offers fair, sub-fair and unfair from simulated proposers who had a different status from their own. We recorded event-related potentials (ERPs) during the presentation of social status information of the proposer (photography and stars) and the offer. Behavioral results showed that sub-fair offers elicited a more response times than fair and unfair offers. Participants responded slower to sub-fair when they were endowed with high status than with low status. Participants when were endowed with high status responded more quickly to unfair offer when the offers were offered by a participant with low-status than by a participant with middle-status. In line with previous studies participants rejected more unfair than sub-fair and fair offers but there was not effect of self status. Findings also showed that other-status influenced rejected to UG offers. Participants when were endowed with high status rejected more unfair offers when the offers were offered by a participant with low-status than by a participant with middle-status. Electrophysiologically, for the presentation of UG offers, the late positivity potential (LPP, 450-750 ms) for fair offers was more positive than for unfair and sub-fair offers. In addition, cues indicating low other social status elicited a more positive late P3 (500-600 ms) than cues indicating middle and high other social status in left occipital electrodes. While that in right occipital electrodes the cues indicating high other social status elicited a more positive late P3 (500-600 ms) than cues indicating middle and low other social status. However the differences between cues of other social status were not statically significant. Therefore the results of this experiment suggests that the interaction between self and other social status modulated the behavioral responses to fairness offer in UG. However, we believe that is necessary to continue investigating the effect of the social hierarchy on neural responses during the distribution of resources.