" Adaptive decision making is the quintessence of rationality, but the items used to assess intelligence on widely accepted tests bear no resemblance to measures of rational decision making. This creates some curious phenomena that we do in fact tend to notice. We do tend to notice, and to find mildly perplexing, "smart people doing dumb things." But the way that we have historically measured intelligence makes this phenomenon not perplexing at all. If by smart
we mean IQ-test smart and by dumb we mean poor decision making, then the source of the phenomenon is clear. IQ tests do not measure adaptive decision making. So if we are surprised at a high-IQ person acting foolishly, it can only mean that we think that all good mental attributes must co-occur with high intelligence-in this case, that rational thinking must go with high intelligence. "

― Keith E. Stanovich , What Intelligence Tests Miss: The Psychology of Rational Thought