The Dunning-Kruger effect is a metacognitive distortion where people with low cognitive abilities overestimate them, and people with high cognitive abilities, on the contrary, underestimate themselves. To put it another way, there are certain mental models in a person’s mind in which he believes wholeheartedly, even if they do not correspond to reality, i.e. his subjective perceptions replace objective reality.Dunning Kruger effect

Speaking of the Dunning-Kruger effect, one cannot but mention the story with which, as they say, “it all began”.

Once a man named MacArthur Wheeler, living in Pittsburgh, disregarding all means of disguise, committed two bank robberies in the middle of the day. As it should be, the banks had security cameras that captured our hero’s face, so the local police had no trouble apprehending him. The fact that the police were able to find Wheeler immediately left him puzzled, and after his arrest, he kept wondering: how could they find him since he had smeared lemon juice on his face (just before, someone told him that lemon juice makes a person invisible to cameras)!

Ridiculous, isn’t it? But the thing is, Wheeler was sure that after he put lemon juice on his face, the cameras couldn’t “see” him. This confidence was the reason why he went to rob banks without a basic mask or at least a stocking over his head. For a normal person, this situation is absurd. But for this robber, his “invisibility” was an irrefutable fact. His unobjectivity was his subjective certainty – this is a particular case of the Dunning-Kruger effect.

Two researchers of human behavior – David Dunning and Justin Kruger – were interested in the above-described event – they decided to study the interesting phenomenon in more detail. They were interested, of course, not in the bank robbery itself, but in the difference between a person’s actual abilities and his perception of them.

Subsequently, Dunning and Krueger hypothesized that people with low ability face two kinds of difficulties:

  • Making poor decisions because of their low ability
  • Unable to recognize that the decisions they make are wrong

To confirm their hypothesis, scientists conducted relevant studies and experiments with a group of people who were first asked to perform a test task designed to measure their abilities in a specific area (sense of humor, grammar, or logical thinking) and then assume the extent of their knowledge and skills in that area.

Through this study, the following experimental findings were obtained:

  • People with low levels of ability tended to significantly overestimate their abilities, and the lower the level of ability, the higher their subjective assessment was;
  • People with a high level of ability, on the contrary, underestimated their potential. This was large because if a certain task seemed simple to a person, he thought it was simple for all other people as well.

This was followed by the second phase of the experiment: participants were asked to examine the test results of the other subjects and then reassess their abilities.the Dunning Kruger effect

People with high levels of ability, comparing themselves to others, realized that they were better than they originally thought they were. Based on this, they adjusted their self-assessment and evaluated themselves much more objectively in the future.

People with low abilities did not change their self-evaluation, since they could not accept that other people were “better” than them and that their level of ability was significantly lower.


The conclusions of Dunning and Krueger’s research are as follows:

incompetent people are usually unaware of their incompetence and largely overestimate their abilities and capabilities without recognizing the abilities of others, and without changing their self-esteem. It is precisely such people who, so to speak, “suffer” from the Dunning-Kruger effect. It has been found experimentally that incompetent people make incompetent decisions and draw erroneous conclusions, and their incompetence is a barrier to understanding and acknowledging these objective facts.