People do not hold questionable beliefs simply because they have not been exposed to the relevant evidence. Nor do people hold questionable beliefs simply because they are stupid or gullible. Quite the contrary. Evolution has given us powerful intellectual tools for processing vast amounts of information with accuracy and dispatch, and our questionable beliefs derive primarily from the misapplication or overutilization of generally valid and effective strategies for knowing. Just as we are subject to perceptual illusions in spite of, and largely because of, our extraordinary perceptual capacities, so too are many of our cognitive shortcomings closely related to, or even an unavoidable cost of, our greatest strengths.
-- Thomas Gilovich, How We Know What Isn't So