Intelligence and the rationality of political preferences

I study the relationship between intelligence and the rationality of political preferences. Intelligence is operationalized as achievement in standard mental ability tests, rationality as consistency between political attitudes and political preferences and consistency as the effect of the interaction between intelligence and political attitudes on political preferences. Political preferences are measured by party affiliation – support for the Democratic versus the Republican Party in the US – and political attitudes are measured on a conservative-liberal dimension. I analyze three large representative American databases and find that for global political attitudes and for specific social attitudes, but not for specific economic attitudes, intelligence is associated with a considerable more attitude-preference consistency (ΔR² of 2.7% 0.9%, and 0.9%, in Study 1, 2 and 3, respectively, corresponding to f² of 0.014, 0.011 and 0.035, respectively). I conclude with a discussion of possible causal processes underlying the observed relationship between intelligence and consistency of political attitudes.