Conventional wisdom (and several psychological theories) claim that political extremism is caused by insecure attachment, ultimately stemming from harsh experiences in childhood; twin data suggests this is wrong

Kleppestø, Thomas H., Nikolai O. Czajkowski, Olav Vassend, Espen Røysamb, Nikolai H. Eftedal, Jennifer Sheehy-Skeffington, Eivind Ystrom, et al. 2021. “Attachment and Politics Are Two Functionally Distinct Systems, and Both Share Genetics with Interpersonal Trust and Altruism.” PsyArXiv. September 1. doi:10.31234/osf.io/3r9em

Abstract: The evolved attachment system maintains proximity and care-giving behavior between parents and offspring, in a way that is argued to shape people’s mental models of how relationships work, resulting in secure, anxious or avoidant interpersonal styles. Several theorists have suggested that the attachment system is closely connected to orientations and behaviors in social and political domains, such that the latter are grounded in the same set of familial experiences as are the different attachment styles. We use a large sample of Norwegian twins (N = 1987) to assess the relationship between attachment styles and two key ideological orientations, right-wing authoritarianism (RWA) and social dominance orientation (SDO), and the role of genetic and environmental influences therein. We also consider the relationship of both sets of traits with the interpersonal orientations of trust and altruism. Results indicate no shared environmental overlap between attachment and ideology, nor even between the two attachment styles or between the two ideological traits, challenging conventional wisdom in developmental, social, and political psychology. Rather, evidence supports two functionally distinct systems, one for navigating intimate relationships and one for navigating social hierarchies, with genetic overlap between traits within each system, and two distinct genetic linkages to trust and altruism. We argue for further genetically informed research in other settings to elucidate the etiology and dynamics of these core aspects of our social and political nature.