The evolutionary psychologist Geoffrey Miller argues in Spent – Sex, Evolution and Consumer Behaviour Viking 2009 that politics is rooted in personality psychology, participatory the big six dimensions of personality as
He has this brilliant comment on how these traits influence political behaviour (page 169)
“The big six personality traits also predict social, political, and religious attitudes fairly well. Liberals are only a little brighter than conservatives on average but they tend to show significantly higher openness (more interest in novelty and diversity), lower conscientiousness (less adherence to conventional social norms), and higher agreeableness (more widespread empathy and “bleeding hearts”). Conservatives show lower openness and (more traditionalism and xenophobia), higher conscientiousness (family value moralism, sense of duty, civic-mindedness), and lower agreeableness (more hard headed, hard hearted support for their self-interests and national interests). ”
However, since the traditional left-right political spectrum has only one dimension, and the big six has six dimensions, it is more accurate to describe the complete range of human political attitudes using the big six. For example, the 1960s New Left was basically more open (freethinking) than the 1930s Old Left. Fascists can be seen as basically lower-intelligence conservatives with lower stability (more fear, distress, anxiety and neuroticism) and even lower agreeableness (more aggressive interests in warfare, torture and genocide). Libertarians can be viewed as basically higher intelligence liberals with slightly higher conscientiousness (faith in social reciprocity and the work ethic), lower agreeableness (distaste for conspicuous sympathy displays), and an extra dollop of extraversion (self-reliant surgency).