Neuroanatomical correlates of social dominance orientation and the contributing role of reward sensitivity
摘要
Social Dominance Orientation (SDO) is a central construct in social psychology that reflects individuals’ preference for group-based hierarchies and intergroup dominance. Despite extensive research on this trait, little is known about its neural underpinnings. Investigating the neuroanatomical correlates of SDO may help clarify the dispositional mechanisms sustaining social hierarchies, revealing how stable brain traits relate to ideological orientation and social behavior. Previous studies have highlighted the potential involvement of specific brain structures, such as the insula, but these findings have yet to be replicated. In this study, we conducted a conceptual replication with methodological refinements by performing region of interest (ROI) analyses on structural 3T MRI data obtained from a sample of 99 young adults. Results revealed a negative correlation between SDO scores and gray matter volume in both the left and right anterior insula. Notably, this region has been consistently linked to socio-emotional processes such as empathy, suggesting that structural variations in this region might relate to the socio-emotional profiles typically associated with individuals high in SDO. In addition, we observed a positive association between a reward-approach personality trait—Sensitivity to Reward (SR)—and SDO scores. Furthermore, the model comprising the left anterior insula volume and SR explained 29% of the variance in SDO, thus underscoring the contribution of this region and the influence of reward sensitivity on socially oriented motivational tendencies.