A hat tip to the elves at No Such Thing as a Fish for bringing this to my attention:
In the field of psychology, the Dunning–Kruger effect is a cognitive bias, wherein persons of low ability suffer from illusory superiority when they mistakenly assess their cognitive ability as greater than it is. The cognitive bias of illusory superiority derives from the metacognitive inability of low-ability persons to recognize their own ineptitude. Without the self-awareness of metacognition, low-ability people cannot objectively evaluate their actual competence or incompetence...
Although the Dunning–Kruger effect was formulated in 1999, the cognitive bias of illusory superiority has been known throughout history and identified by intellectuals, such as the philosopher Confucius (551–479 BC), who said, “Real knowledge is to know the extent of one’s ignorance”; by the playwright William Shakespeare (1564–1616), who said, “The fool doth think he is wise, but the wise man knows himself to be a fool” (As You Like It, V. i.); by the naturalist Charles Darwin (1809–1882), who said, “Ignorance more frequently begets confidence than does knowledge”; and by the philosopher and mathematician Bertrand Russell (1872–1970), who said, “One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision...
More at the link, and this
example cited by David Dunning as the trigger for his initial publication:
Wheeler had walked into two Pittsburgh banks and attempted to rob them in broad daylight. What made the case peculiar is that he made no visible attempt at disguise. The surveillance tapes were key to his arrest. There he is with a gun, standing in front of a teller demanding money. Yet, when arrested, Wheeler was completely disbelieving. “But I wore the juice,” he said. Apparently, he was under the deeply misguided impression that rubbing one’s face with lemon juice rendered it invisible to video cameras...
If Wheeler was too stupid to be a bank robber, perhaps he was also too stupid to know that he was too stupid to be a bank robber — that is, his stupidity protected him from an awareness of his own stupidity.