http://www.unz.com/jthompson/folie-a-deux/

Dwelling on this a moment, one thing becomes clear: many people are immensely deluded. They think themselves two standard deviations brighter than they really are.
In fact, the scores on the Raven’s Matrices were corrected for two decades of Flynn Effect. Without the correction, the scores would still be 1.5 standard deviations too high. Lake Wobegon on steroids.
Back to the main point: people seem to be over-estimating their intelligence by 30 IQ points and their partner’s IQ by 38 points in the case of women doing the judgments, and 36 points in the case of men doing the judgments. People are deluded about their abilities, and deluded about their partners’ abilities. Delusion plus 7 points. This is dreadful, but also highly illuminating. No wonder so many people hate actual intelligence tests.
People who are actually below the “average” of 100 think they’re 2 SD brighter than they actually are.
Ladies and Gentlemen, I give you the Democratic Party of the United States of America.
P.S. The GOP is full of cucks, not morons, but cucks just the same.