The Dunning-Kruger Effect

by Craig Shrives

What Is the Dunning-Kruger Effect?

In Critical Thinking, the Dunning-Kruger Effect is the tendency for incompetence to prevent recognizing incompetence.
What is the Dunning Kruger effect?

Easy Definition of the Dunning-Kruger Effect

If you're untrained, inexperienced or don't fully understand your environment, don't trick yourself into thinking you're doing well. You might be suffering from the Dunning-Kruger Effect.

Academic Definition of the Dunning-Kruger Effect

The Dunning-Kruger Effect is the tendency for unskilled people to make poor decisions or reach wrong conclusions, but their incompetence prevents them from recognising their mistakes. It links well with the old adage: "Ignorance is bliss."

The Dunning-Kruger Effect Graph

This is the Dunning-Kruger Effect graph. Notice how confidence rockets when a little experience is achieved. However, as experience grows, people start to understand how little they know and confidence drops until experience grows. Also, notice how the confidence of the person who has almost zero knowledge is so much higher than that of a full-on expert.
Graph of Dunning Kruger Effect
In uncovering this tendency, Justin Kruger and David Dunning of Cornell University were partly influenced by this observation:

"Ignorance more frequently begets confidence than does knowledge." (Charles Darwin)

An Example of the Dunning-Kruger Effect

Unlike yourself, I'm a great writer

Most people are required to write stuff for some reason or other. This is one area where the Dunning-Kruger Effect is prevalent. If you don't know you can't use an apostrophe to show a plural (e.g., two solution's) or you don't know that semicolons can't be used for introductions (e.g., I like the following; A, B and C), then these mistakes don't register as mistakes when you bash out your written correspondence. To the rest of the world, you look a bit of a dunce, but, as far as you're concerned, you're a great writer. Your incompetence has stopped you seeing your incompetence. The Dunning-Kruger Effect is the reverse side of the coin to this football chant:

"You're shit, and you know you are." (Football chant)

With the Dunning-Kruger Effect, they don't know they are.

According to Dunning and Kruger, ignorance is behind a great deal of incompetence. They assert that incompetent people will:
  • Overestimate their abilities.
  • Fail to recognise genuine ability in others.
  • Not recognise the extremity of their inadequacy.
Oh, if you didn't spot that the "Unlike Yourself" in the title of this example should be "Unlike You", you could be one of those unwittingly whacking loads of grammar errors into your work without realising it. Eeek! Solution? Use competent proofreaders.

Another Example of the Dunning-Kruger Effect

Why does it keep doing that?

Microsoft Office applications (e.g., Word, PowerPoint, Excel) are at their most frustrating when they try to help you. Microsoft Word's tendency to change the font type and size after you cut and paste something is a classic example. But whose fault is that? In our office, it's always MS Word's fault when the auto-numbering kicks in without being asked or an embedded image starts choosing its own location on the page. But, in truth, it's the user's fault. Most people learn the MS office applications on the job. They become quite proficient at using the normal functions, but start losing their way around the processor when the more-out-of-the-ordinary functions are required. In my experience, very few people actually go on a course to learn how to use the MS applications. The difference in proficiency between the course-trained people and the on-the-job learners is marked.

Many people find that once they've done a course, the "gremlins" that wound them up suddenly start making sense. Document templates, style and format templates, multiple clipboards, mail merge, image manipulation and auto-numbering all transform into useful tools after training. Before training, they're just things to turn off or work around. Until the users' incompetency has been addressed by attending a course, those things that make their lives a misery when using MS applications will remain the application's fault and not theirs. If this sounds like how MS applications treat you, then I'm afraid you might be suffering from the Dunning-Kruger Effect.

There is some good news. The Dunning-Kruger Effect is not permanent. People often become aware of and acknowledge their own previous lack of ability after training...or time.

A Practical Application for the Dunning-Kruger Effect

Win an argument with two sentences

One of the best things about the Dunning-Kruger Effect is using the term in arguments. If you say to someone "your incompetency is preventing you from seeing your incompetency" and then add "it's a classic example of the Dunning-Kruger Effect", you might as well start a lap of honour around the room doing I'm-the-champion hands. You'll have just bashed them hard with a tight circular argument with no chinks in its armour and underpinned it with some academic name-dropping. It will rock them back onto their heels.

Summary of the Dunning-Kruger Effect

If you think somebody's lack of ability or experience is preventing them from seeing their own failings, tell them they are suffering from the Dunning-Kruger Effect.
Help Us To Improve

  • Do you disagree with something on this page?
  • Did you spot a typo?
  • Do you know a bias or fallacy that we've missed?
Please tell us using this form

See Also