Source: Very Well Mind
The Dunning-Kruger effect is a type of cognitive bias in which people believe that they are smarter and more capable than they really are. Essentially, low ability people do not possess the skills needed to recognize their own incompetence. The combination of poor self-awareness and low cognitive ability leads them to overestimate their own capabilities.
The term lends a scientific name and explanation to a problem that many people immediately recognize—that fools are blind to their own foolishness. As Charles Darwin wrote in his book The Descent of Man, “Ignorance more frequently begets confidence than does knowledge.”
An Overview of the Dunning-Kruger Effect
This phenomenon is something you have likely experienced in real life, perhaps around the dinner table at a holiday family gathering. Throughout the course of the meal, a member of your extended family begins spouting off on a topic at length, boldly proclaiming that he is correct and that everyone else’s opinion is stupid, uninformed, and just plain wrong. It may be plainly evident to everyone in the room that this person has no idea what he is talking about, yet he prattles on, blithely oblivious to his own ignorance.