I happened to stumble upon this particular Wikipedia Entry:
‘The Dunning–Kruger effect is a cognitive bias in which the unskilled suffer from illusory superiority, mistakenly rating their ability much higher than average. This bias is attributed to a metacognitive inability of the unskilled to recognize their mistakes.
Actual competence may weaken self-confidence, as competent individuals may falsely assume that others have an equivalent understanding. As Kruger and Dunning conclude, “the miscalibration of the incompetent stems from an error about the self, whereas the miscalibration of the highly competent stems from an error about others”‘
If you, like me, have just spent an inordinate amount of time arguing with a skull-grindingly idiotic antagonist, you are no doubt nodding your head in recognition. It’s possible even possible that you too may be suffering from this delusion, but if you are concerned about it, then you are probably not. The article unfortunately didn’t discuss the prevalence of this effect (beyond some unsourced claim that it is less prevalent in Europe), but my own naive hypothesis would be that the past thirty years’ focus on “encouraging self-esteem” in children is probably at least partially to blame.