The lesson isn’t that dumb people are overconfident, according to its co-creator. It’s that you are. Few psychological rules have as high a public profile as the Dunning-Kruger effect. Way back in 1999, David Dunning and Justin Kruger showed that the people who were least competent at a given task were also the most confident in their abilities. Meanwhile, the most skilled are the most unsure. In the 26 years since Dunning and Kruger published their landmark paper, scientists have debated the details of the findings. But the public has run with it. It’s not hard to see why. A theory that states the dumbest among are often the loudest and most overconfident seems to explain so much about modern life. Plus, it’s a handy grenade to throw in a social-media fight. Search “Dunning-Kruger Effect” online and you’ll find huge numbers of people labeling those they disagree as obvious cases of the effect in action. It’s a satisfying way to dunk on your opponents. But there’s one big problem…
