No shit, Sherlock
A recent study suggests that not only are right-wing political affilations correlated with prejudiced atttitude, but so is low intelligence.
Personal observation bears out the correlation. The only question left is the direction of causality. is it ignorance that makes people become Republicans/Conservatives/Blairites/swivel-eyed Islamophobes, or is it immersion in one of those cults which stunts the intelligence by systematically replacing facts with dogmas and truth with invention?