Stupid People Don’t Know They Are Stupid

Updated on December 18, 2017

There is no shortage in the supply of incompetent people. According to the BBC, “More than one in every 10 workers in England are incompetent at their jobs, a survey of 72,100 employers suggests.” The really frustrating thing for the rest of us is that many of those useless people are unaware they are bunglers.

They are the Russian woman who checked to see how much gas was in her tank at a gas station by using a lighter. Or, the hold-up guy in Long Beach, California whose gun failed to fire so he peered down the barrel and pulled the trigger.


Blindly Ignorant

In 1999, two psychologists at Cornell University, David Dunning and Justin Kruger, studied how people fail to recognize the difference between accuracy and error. They published their results in a paper that aptly describes their findings: Unskilled and Unaware of it: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments.

People who are not very smart suffer a dual burden. First they are dim-witted and second they lack the cognitive ability to recognize this. In their paper Dunning and Kruger “... found that participants scoring in the bottom quartile on tests of humor, grammar, and logic grossly overestimated their test performance and ability. Although their test scores put them in the 12th percentile, they estimated themselves to be in the 62nd.”

So, those who scored near the bottom self-assessed themselves to be in the smartest third.

Similarly, in a study of the faculty at the University of Nebraska, 90 percent of the teaching staff rated themselves to be above average, which, of course, is mathematically impossible.

And, who amongst us has not come across a bad driver who is convinced he or she possesses the skill of a Formula One champion?

The Incompetent Bank Robber

Dunning and Kruger began their study because of the actions of a monumentally stupid crook.

McArthur Wheeler robbed two banks in Pittsburgh without wearing a mask. Security camera video of the robberies was played on local telecasts clearly showing the face of the criminal. Within minutes tips as to his identity reached police and before the day was done McArthur Wheeler was in custody.

He couldn’t believe his bad luck and told detectives “But, I wore the juice.”

It seems Wheeler had found out that lemon juice can be used as invisible ink. So, he reasoned, if he put lemon juice on his face he would be invisible to security cameras.

He tested the hypothesis by taking a Polaroid of his lemon juice-covered face and, sure enough, his face was invisible. Police were baffled by this but concluded Wheeler was as inept at photography as he was at bank robbing.

New York Magazine reports that when David Dunning read about the hapless bank robber “He saw in this tale of dim-witted woe something universal. Those most lacking in knowledge and skills are least able to appreciate that lack.”

The idea of the Dunning-Kruger Effect can be traced back a long way. In 1698, a collection of letters was published in which an anonymous writer opined “Twas well observed by my Lord Bacon, that a little knowledge is apt to puff up, and make men giddy …”


Performance Reviews

The Dunning-Kruger Effect is something managers and human resources people have to tussle with constantly.

According to Forbes “… only 39 percent of employees handle constructive criticism by systematically dissecting every step leading up to the thing they just got criticized for.” These are people who are intelligent, recognize they are not perfect, and are motivated to correct their deficiencies.

As Dunning and Kruger observe “… most people have no trouble identifying their inability to translate Slovenian proverbs, reconstruct a V-8 engine, or diagnose acute disseminated encephalomyelitis.”

But that leaves 61 percent who don’t deal well with critical feedback. Of course, they are not all suffering from the Dunning-Kruger Effect, but many are.


A Famous Sufferer

U.S. President Donald Trump, by the estimation of many, suffers from the Dunning-Kruger Effect. He endlessly brags about his abilities:

  • “… my I.Q. is one of the highest - and you all know it! Please don’t feel so stupid or insecure, it’s not your fault.”
  • “I’m very highly educated. I know words. I have the best words.”
  • “I’m proud of my net worth, I’ve done an amazing job …”
  • “I alone can fix it.”

Of course, the world has come to understand that he is challenged by language. Here’s The Guardian “His spelling and grammar are disastrous, he contradicts himself, trails into incoherence …” The Washington Post suggests he speaks at a Grade Six level.

Through his amazing business acumen he has led his companies into bankruptcy four times. He even managed to go broke running a casino.

As for fixing America politically, he has racked up an impressive list of failures.

Columnist George Will (Washington Post, May 2017) points out that, “… the problem isn’t that he does not know this or that, or that he does not know that he does not know this or that. Rather, the dangerous thing is that he does not know what it is to know something.”

That’s a clear definition of the Dunning-Kruger Effect.

William Poundstone (Psychology Today, January 2017) reminds us all to have a little humility about our competence: “You may not harbor illusions about your ability to be Commander in Chief or devise a brilliant health-care plan. Yet in dozens of quieter ways, we all suffer from an incurable delusion of competence.”


Bonus Factoids

Not entirely unrelated to the Dunning-Kruger Effect is the Peter Principle. Educator Lawrence Peter put forward this theory in 1969, which states broadly that organizations promote people based on their performance in their current position rather than on whether they have the skills to master their new post. Taken to its logical extreme, the Peter Principle says that eventually people are raised to a level at which they become incompetent.

Scott Adams, the Dilbert cartoonist, has proposed the Dilbert Principle. Simply stated, incompetent employees are promoted ahead of competent workers. This shuffles them away from productive work into positions where they can cause the least amount of damage to the organization.


  • “One in 10 Workers ‘Incompetent.’ ” BBC News, February 3, 2004.
  • “Unskilled and Unaware of it: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments.” Kruger J, Dunning D, Journal of Personality and Social Psychology, December 1999.
  • “The Dunning-Kruger Effect Shows Why Some People Think They’re Great Even When Their Work Is Terrible.” Mark Murphy, Forbes, January 24, 2017.
  • “Trump Has a Dangerous Disability.” George Will, Washington Post, May 3, 2017.
  • “The Internet Isn’t Making Us Dumber — It’s Making Us More ‘Meta-Ignorant.’ ” William Poundstone, New York Magazine, July 27, 2016.
  • “The Dunning-Kruger President.” William Poundstone, Psychology Today, January 21, 2017.

Questions & Answers


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      • k@ri profile image

        Kari Poulsen 7 months ago from Ohio

        LOL, I really enjoyed this. Love John Cleese. But it makes me wonder what I am blind about. :)

      • Glenis Rix profile image

        GlenR 7 months ago from UK

        Perhaps, then, if people can't recognise their own stupidity, we are all a little stupid?

      • Rupert Taylor profile image

        Rupert Taylor 7 months ago from Waterloo, Ontario, Canada

        Thanks Paula. Glad I was able to bring a little levity into your life, but it remains that the Stupid-in-Chief is in the White House and that affects us all.

      • fpherj48 profile image

        Paula 7 months ago from Beautiful Upstate New York

        Oh LOL...Rupert, I'm wiping the tears of laughter from my face! The John Cleese video and even funnier, the "stupidity to extreme" video had me howling....

        Thanks so much. I really needed this moment of hilarity! I have just had an incredible day, out & about, running errands and also running into so many of these very people! LOL As annoying as this can be and the level of frustration we experience when finding we must deal with yet another Moron, we truly must laugh in the end. There's really not much more we can do to fix "Stupid!!"

        If we were grading this article, you get an A+ from me! Paula