The phrase Dunning-Kruger effect, and its variants, designate a postulated cognitive bias whereby people who have little ability in, or knowledge of, a particular task or subject tend to overestimate their capabilities, while those who are highly skilled or knowledgeable may tend to underestimate theirs.

This phrase occurs, for example, in The ‘leftwing economic establishment’ did not bring Liz Truss ¹ down. Reality did, by the British journalist Polly Toynbee (born 1946), published in The Guardian (London and Manchester, England) of Monday 6^th February 2023:

Incidentally, observers puzzled by the Truss phenomenon may like to check the Dunning-Kruger effect: “Unskilled and unaware of it: how difficulties in recognising one’s own incompetence lead to inflated self-assessments.”

¹ This refers to the British politician Mary Elizabeth Truss (born 1975), Leader of the Conservative Party from Monday 5^th September to Monday 24^th October 2022, and Prime Minister of the United Kingdom from Tuesday 6^th September to Tuesday 25^th October 2022.

The phrase Dunning-Kruger effect refers to the U.S. social psychologists David Dunning and Justin Kruger, who described the effect in Unskilled and unaware of it: how difficulties in recognizing one’s own incompetence lead to inflated self-assessments, published in the Journal of Personality and Social Psychology (American Psychological Association) of December 1999.

The earliest occurrences of the phrase Dunning-Kruger effect and variants that I have found are as follows, in chronological order:

1-: From Business filter: A weekly catch of stories you don’t want to miss, published in The Boston Globe (Boston, Massachusetts, USA) of Monday 7^th January 2008:

Ignorant blowhards

The Dunning-Kruger effect is hurting business. Ever hear of it? Me neither. Here’s the crux of it: “Ignorance more frequently begets confidence than knowledge.” Translation: Studies show that incompetent people are more likely to be convinced they’re superstars. And the confidence exhibited by these ignorant blowhards makes them appear to be high performers. Meanwhile, the truly competent people often underestimate their competence. Why? Because “the more you know, the more you focus on what you don’t know.” Vicious circle. How to minimize this? Provide measurable standards for performance, encourage debate and dissension, and “show confidence in your best employees, even when they don’t have confidence in themselves.”

2-: From the review of Souvenir, produced at the Falcon Theatre, Burbank, California, starring Constance Hauman as Florence Foster Jenkins—review by Charlotte Stoudt, published in the Los Angeles Times (Los Angeles, California, USA) of Friday 12^th February 2010:

Singer splits ears and sides

Dr. House ² would call it the Dunning-Kruger Effect: a cognitive bias that leads incompetent people to overrate their abilities.
But Florence Foster Jenkins, the infamous tone-deaf socialite singer, was just living her dream. Her unlikely triumph is the subject of “Souvenir,” Stephen Temperley’s droll Broadway hit, now at the Falcon Theatre.

² This refers to Dr. Gregory House, interpreted by the British actor Hugh Laurie (born 1959), in House M.D. (2004-2012), a U.S. medical drama television series.

3-: From the column Your Saturday rude awakening, by Neal Boortz, published in The Atlanta Journal-Constitution (Atlanta, Georgia, USA) of Saturday 19^th February 2011:

Knowing little, but certain of much

I learned of a wonderful scientific study this week, and I can’t wait to share it with you. You’re going to want to write this down or maybe just save this column. Within no time at all it will come in handy when a co-worker spouts off some bit of what he assumes to be wisdom, which sounds like utter nonsense.
Just look around—tilt your head knowingly—and say, “Dunning-Kruger effect.”
What effect? Dunning-Kruger, named after the two psychologists, David Dunning and Justin Kruger, who essentially proved what most of us already knew.
Example: Have you ever marveled at how young people, freshly arrived at their college campus and free from full-time parental oversight for just a matter of weeks, suddenly acquire the knowledge necessary to solve virtually all of the world’s social and economic problems?
The answer is the Dunning-Kruger effect: the theory that the less you know the more you think you know. There! Now it hits home, doesn’t it! You know that guy!
Dunning and Kruger conducted their studies on undergraduates at Cornell University. They looked at these students’ self-assessments in three areas: logical reasoning, grammatical English usage and humor. After these students made their own self-assessment they were tested.
The students who rated themselves the highest in these skill areas scored the lowest on the practical tests. But what about those students who scored well on the tests? What about their pre-test self-assessments? Interestingly enough, they had underestimated their skills in these areas.
Direct from the Dunning-Kruger study as published in the Journal of Personality and Social Psychology—for a given skill, incompetent people will:
1) Tend to overestimate their own level of skill. 2) Fail to recognize genuine skill in others. 3) Fail to recognize the extremity of their inadequacy. 4) Recognize and acknowledge their own previous lack of skill, if they can be trained to substantially improve.
Now you understand why our know-it-all young college students with solutions to all of the world’s problems come to a gradual understanding—with the passage of semesters and a little work experience thrown in—that they really don’t know all that much after all. It’s a real pity we made the mistake of giving them the privilege of voting before that wisdom kicked in.
Now I am going to use my 40-plus years of talk radio and discussions with possibly a quarter-million callers to lay claim to my own degree in social psychology. Lord knows I’ve endured my share of Dunning-Kruger sufferers over the years.
Dunning-Kruger, you see, seems to be unique to the United States! Studies conducted in Asia, for instance, show that Asian students are able to make a more realistic assessment of their own abilities.
Now why would that be?
One of my co-workers announced a few weeks ago that she would not be coming to work one particular Friday. Her son was getting an award at his wonderful Atlanta government school. Her son encouraged her to skip the ceremony and go to work. “Gosh, Mom! Everybody gets an award! It’s nothing special!”
So there you go, the “self-esteem” thing. Government schools handing out unearned awards, inflating grades, eliminating the dreaded “F” and not using red ink in grading papers because that would be negative. We even had teachers in a government school near Orlando showing up with special T-shirts after the school received an “F” in grading on state standards. The T-shirts? “F” is for “Fantastic!”
When you tell failing students in failing government schools that they’re doing just fine, thank you very much, they become wonderful little Dunning-Kruger trainees. Then life comes along and knocks them back a peg or two.