Being smart makes you more prone to  mental errors. study in the Journal of Personality and Social Psychology set out to study the "bias blind spot," the inclination to think, in short, that other people are stupider than you are. The study described various cognitive biases
to 482 participants, then gave them several questions with seemingly obvious, but wrong, answers. Various measures of intelligence, including SAT scores and cognitive test scores, found that smarter people were more likely to answer these questions incorrectly. Greater cognitive ability resulted in a greater bias blind spot. (AskMen.com)