Authoritarianism and the brain: Structural MR correlates associated with polarized left- and right-wing ideology traits

Authoritarian attitudes across the political spectrum foster radical behaviors, which adversely affect the social fabric. Both left-wing (LWA) and right-wing (RWA) forms of authoritarianism have been described in relation to their psychological correlates, yet little is known about their neurobiological basis. In this study, we explored brain structural correlates (e.g., in cortical thickness (CT) and gray matter (GM) volume) of authoritarianism. For this purpose, we assessed authoritarian dispositions in a sample of 100 young adults and collected 3 T MR images. Images were computed using the CAT12 toolbox. Behaviorally, both the LWA and RWA were positively associated with negative urgency; the LWA also showed a robust positive association with trait anxiety. At the neural level, results showed a negative correlation (r = -0.48) between RWA and a GM volume cluster located in the dorsomedial prefrontal cortex (dmPFC). In addition, we also observed a negative correlation (r = -0.41) between the LWA anti-hierarchical aggression subscale and a CT cluster located in the right anterior insula. Additionally, the resulting clusters converged with further left-wing and right-wing ideology scales related to LWA and RWA, thus providing a robustness check. These results are supported by previous studies showing the relevance of the dmPFC and the anterior insula on social cognition and empathy/inhibitory control, respectively.