What makes people vote Republican? Why in particular do working class and rural Americans usually vote for pro-business Republicans when their economic interests would seem better served by Democratic policies? We psychologists have been examining the origins of ideology ever since Hitler sent us Germany's best psychologists, and we long ago reported that strict parenting and a variety of personal insecurities work together to turn people against liberalism, diversity, and progress. But now that we can map the brains, genes, and unconscious attitudes of conservatives, we have refined our diagnosis: conservatism is a partially heritable personality trait that predisposes some people to be cognitively inflexible, fond of hierarchy, and inordinately afraid of uncertainty, change, and death. People vote Republican because Republicans offer "moral clarity"—a simple vision of good and evil that activates deep seated fears in much of the electorate. Democrats, in contrast, appeal to reason with their long-winded explorations of policy options for a complex world.