The Dunning-Kruger Effect

Have you ever noticed how ignorant people often speak with great confidence? And truly smart people constantly question themselves? In the late 90s, two researchers set out to explain this phenomenon and came up with the Dunning-Kruger effect.
The Dunning-Kruger Effect

Last update: 12 September, 2020

The Dunning-Kruger effect is a cognitive bias that makes less competent people overestimate their abilities and more competent people underestimate them. We’ve all experienced or witnessed this at some point in our lives. When ignorant people think they know everything or truly intelligent people think they’re ignorant, the Dunning-Kruger effect is at play.

People who suffer from this bias have an illusion of their own superiority. They believe they’re better than the average person. They also tend to underestimate those who are the most competent.

A 1999 study carried out by Dunning and Justin Kruger, two researchers from Cornell University, demonstrated this effect. One very curious thing about this study is that the Dunning-Kruger effect appears to be unique to Western society. When they tried to repeat their study in Asia, they found that the exact opposite thing occurred.

What’s behind the Dunning-Kruger effect?

The Dunning-Kruger effect posits that incompetent people don’t have the necessary abilities to distinguish themselves from those more skilled than them. People who lack the knowledge or the wisdom to perform often aren’t aware of their shortcomings. Scientists attribute their lack of awareness to deficient metacognitive skills.

A guy mansplaining something to a woman.

In other words, the same incompetence that leads them to make bad decisions is what makes it impossible for them to recognize their problem. They can’t recognize it in other people either. In fact, there’s a whole group of intellectually mediocre people who make a living believing that they’re charismatic geniuses. In general, they do it because other people find it attractive.

“An intellectual is usually someone who isn’t exactly distinguished by his intellect. He claims that label to compensate for his inadequacies. It’s as old as that saying: “Tell me what you boast of and I’ll tell you what you lack”. Our daily bread. The incompetent always present themselves as experts, the cruel as pious, sinners as devout, usurers as benefactors, the small-minded as patriots, the arrogant as humble, the vulgar as elegant, and the feeble-minded as intellectual.”

-Carlos Ruiz Zafón-

The results of Kruger and Dunning’s studies could be interpreted differently. However, the effect is usually the following: of all the people who carry out a concrete task, the least skilled believe that they’re very prepared to complete it. On the other hand, the best tend to not have a lot of confidence in their skills.

The reason why incompetent people are successful

The explanation lies in a fascinating idea called the just-world fallacy. According to this belief, you deserve the results that you get in life. People who think this way believe that they are where they are in life due to their merits.

What we can see is that incompetent people believe that they’re better than they really are. However, in general, they don’t believe they’re as good as those who are actually skilled and competent. It’s important to point out that Dunning and Kruger have never proved that incompetent people think they’re better than competent people. They just believe that they’re better than they are, and they shout it from the rooftops.

There is a significant difference between the way incompetent people perceive their performance and what it actually is in reality. People who are highly competent have a better idea of their actual performance and abilities.

The Dunning-Kruger effect makes it difficult for truly un-skilled people to try to improve. Until they recognize their faults, they’ll never be able to overcome them. On the other hand, this cognitive bias keeps those who are already skilled from doing their absolute best. That’s because having confidence in yourself is crucial for success.

Examples of the Dunning-Kruger effect

If you aren’t very good at languages, for example, it might be hard for you to see that. This is because you lack the necessary skills to be able to distinguish a good foreign language speaker from a bad one. If you can’t hear the difference between two different phonemes, how could you know who has good pronunciation and who doesn’t? If you only know a few words of a foreign language, how could you compare the size of your own vocabulary with that of others?

Or maybe you’ve heard someone speak many times about something they know absolutely nothing about. Those who do know, on the other hand, stay quiet. You can even see examples of this in the media. People pay more attention to those who speak with confidence even if they aren’t telling the truth.

A guy with question marks above his head.


Basically, the Dunning-Kruger effect states that ignorant people think they’re good and those who are really good believe themselves to be incompetent.

Overcoming this effect is crucial for our society. Consequently, if you ever think you know the truth, speak up. We need more wise people to have confidence in themselves and share their knowledge with others.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.