Dunning-Kruger Effect: A cognitive bias that causes unskilled people to mistakenly rate their ability as much higher than average. As Charles Darwin wrote in 1871 in The Descent of Man: “Ignorance more frequently begets confidence than does knowledge.”
The effect is named for David Dunning and Justin Kruger, social psychologists at Cornell University, who co-authored “Unskilled and Unaware of It,” published in the December 1999 issue of the Journal of Personality and Social Psychology.
From the abstract:
People tend to hold overly favorable views of their abilities in many social and intellectual domains. The authors suggest that this overestimation occurs, in part, because people who are unskilled in these domains suffer a dual burden: Not only do these people reach erroneous conclusions and make unfortunate choices, but their incompetence robs them of the metacognitive ability to realize it. … Paradoxically, improving the skills of the participants, and thus increasing their metacognitive competence, helped them recognize the limitations of their abilities.
Dunning got the idea to do this research from a news item he wrote read about a bank robber who believed that rubbing lemon juice on his face would render him invisible to surveillance cameras. (At least, that’s what he told the cops after his arrest.)
For their work in this area, Dunning and Kruger were awarded the 2000 Ig Nobel Prize in psychology. The Ig Nobel Prizes have been presented each year since 1991 “to honor achievements that first make people laugh, and then make them think.”
The Dunning-Kruger effect is occasionally invoked in political contexts. (“Dunning-Kruger Sarah Palin” yields many examples.) The term came up just last week in the New York Times blog of economist Paul Krugman, in which Krugman discussed the nonpartisan Tax Policy Center’s report on presidential candidate Mitt Romney’s tax plan. He concluded that the plan was “a Dooh Nibor—that is, a reverse Robin Hood.” The Romney campaign, Krugman wrote in an update, “responded with deep voodoo, invoking the supposed fabulous growth effects from his tax cuts.”
That provoked a comment from “Doug”:
I’m becoming more and more convinced that, not only can the average Tea Partier not understand any of the math that goes into budget analysis, they deny that anybody ELSE can either -- even (especially?) experts with advanced degrees like Dr. K. These people really, honestly believe that math DOESN’T WORK; that nobody can know just how ridiculous Romney's numbers are. They assume we’re just being as politically motivated and as ignorant as they are themselves. …
It’s the Dunning Kruger effect, pure and simple. They assume, since the numbers have no meaning to them, that the numbers simply have no meaning at all. No amount of cogent analysis is ever going to pierce that veil.
Errol Morris, the documentary filmmaker, interviewed David Dunning in 2010 for a New York Times Opinionator blog post about anosognosia, the condition of being unaware of one’s own disability. Dunning said he’d been interested in former Secretary of Defense Donald Rumsfeld’s famous “unknown unknowns” quote, delivered in a 2002 NATO press conference. Dunning told Morris:
Put simply, people tend to do what they know and fail to do that which they have no conception of. In that way, ignorance profoundly channels the course we take in life. And unknown unknowns constitute a grand swath of everybody’s field of ignorance.