Social Dominance Orientation and Perceived Similarity modulate the attracting power of the gaze of politicians on their electors. An fMRI study

Although automatic, gaze-following (GF) behavior is modulated by the interaction between the ideology of an onlooker and the political affiliation of a model. Here, we investigated the neural correlates of in-group political affiliation using a GF paradigm. During fMRI scanning, right- and left-wing participants were requested to make saccadic movements with respect the instruction given by a central fixation point (FP). The FP was located on the face of Italian political leaders (Berlusconi, Bersani) or either opinion-makers (Vespa, Floris) (respectively of a centre-right or centre-left coalition) and gazing at the same (congruent) or different (incongruent) location. After scanning, we acquired measures of Perceived Similarity and Social Dominance Orientation (SDO) for each participant. In keeping with our previous findings, behavioral data showed higher interference for in-group than out-group political affiliation in right wing participants. Interestingly SDO scores predicted the in-group effect. The analysis of the Incongruence-related BOLD signal (IE: incongruent>congruent) revealed a significant activation of left Frontal Eye Field, right Supra-Marginal Gyrus (rSMG) and right Middle Cingulate Cortex (rMCC). ROI analysis showed that in-group vs. out-group Perceived Similarity scores predicted rSMG and rMCC activations associated with the IE of in-group as compared with the outgroup. This result indicates that participants perceiving themselves as ‘similar to in-group’ showed greater engagement of rSMG and rMCC as a function of IE for in-group personage. Finally, we found an interaction between SDO and the group in predicting the rSMG activity for the IE of in-group vs. out-group personage.