The Dunning-Kruger effect isn’t what everyone thinks it is: the original 1999 study found bottom-quartile performers overestimated their standing by about 50 percentile points, not that confident people are stupid
The pop version of Dunning-Kruger — confident people are stupid, smart people are humble — bears almost no resemblance to what the 1999 paper actually found, and the misreading has become the internet's favourite rhetorical weapon.