A study published in Neuroscience by researchers at Spain's University of Zaragoza scanned the brains of 100 young adults and found structural differences in those who hold authoritarian beliefs — on both the left and the right. Right-wing authoritarians had lower grey matter volume in the dorsomedial prefrontal cortex, a region involved in understanding other people's thoughts and perspectives. Left-wing authoritarians had less cortical thickness in the right anterior insula, associated with emotional empathy and behavioral inhibition. Both groups were more impulsive in emotionally negative situations than their less-authoritarian peers.
The study is apparently the first to compare left- and right-wing authoritarianism in brain imaging rather than grouping them together. Lead author Jesús Adrián-Ventura, who runs an interdisciplinary research group called PseudoLab that studies political extremism, noted that left-wing authoritarians also tended to be more anxious. The sample was 100 Spanish adults ages 18–30 with no psychiatric history, which means the findings are suggestive rather than definitive — but the left/right split in which brain regions differ is striking.
