In the U.S., people who are strongly liberal or strongly conservative tend to be better educated and better informed than moderates. Sure, some moderates are moderate because they understand each sides' arguments perfectly, but many are moderate because they aren't very interested in politics.
But, what happens when you disentangle the effects of IQ and education from each other?
Heiner Rindermann, the German psychologist who has been doing a lot of interesting IQ work, has co-authored a new paper comparing IQ to ideology among Brazilians, after adjusting for other factors. (I don't enough about politics in Brazil to say how well this would map to the U.S.)
Rindermann, H., Flores-Mendoza, C. & Woodley, M. A. (2012). Political orientations, intelligence and education. Intelligence, 40(2), 217-225.
• Intelligence is an attribute of a “burgher” worldview and lifestyle.
• Intelligence works via insight, self-interest, and ethical and cultural effects.
• Intelligence had a positive impact on having a political opinion.
• Intelligence had a positive impact on political centrality.
• Education promoted orientations more to the left.
The social sciences have traditionally assumed that education is a major determinant of citizens’ political orientations and behavior. Several studies have also shown that intelligence has an impact. According to a theory that conceptualizes intelligence as a burgher (middle-class, civil) phenomenon – intelligence should promote civil attitudes, habits and norms like diligence, order and liberty, which in turn nurture cognitive development – political orientations should be related to intelligence, with more intelligent individuals tending towards less extreme political orientations. In a Brazilian sample (N=586), individuals were given the Standard Progressive Matrices (SPM) and a questionnaire measuring age, sex/gender, income, education and political orientations. Firstly, intelligence has a positive impact on having any political opinion. Among persons with opinions those with the highest IQ’s were found to be politically center-right and centrist respectively. The relationship held after correcting for gender, age, education and income. In a path-analysis, only intelligence had a positive impact on political centrality, whereas education promoted orientations that were farther from the center. These results are discussed in the context of results from other studies in different countries and in the context of different theoretical models on the relationship between political attitudes and IQ.
So, at a given level of IQ, more education pushes people either to the left or, less often, toward the right. At a given level of education, more IQ pushes people toward a point a little right of center. At least in Brazil ...