The Dunning-Kruger effect (Dunning–Kruger effect; DKE) is a psychological phenomenon whereby people with little knowledge or skill in a particular field tend to overestimate their own abilities. In contrast, those who actually possess a high level of knowledge or experience often underestimate their own abilities.

The phenomenon is named after the two psychologists, David Dunningand Justin Kruger, who conducted research in 1999 during which they observed that the least competent individuals are those most prone to overestimating their own performance.

This effect occurs because those who lack sufficient knowledge are unable to recognise their own ignorance and shortcomings, whilst those who have a good understanding of the subject in question are aware of the limits of their own knowledge.

Right, let’s delve a little deeper into the explanation of this phenomenon!

The most common way of measuring the Dunning–Kruger effect is by comparing self-assessment with objective performance. Self-assessment is sometimes referred to as subjective ability, as opposed to objective ability, which corresponds to actual performance.

Based on some form of objective measurement, the two researchers divided the test participants into four groups according to their objective ability. They were given tests to complete, but before the results were assessed, they had to estimate their expected results. Their analysis revealed that the participants with lower ability (Group 1) consistently overestimated their expected results, that is, their knowledge:

This research clearly corroborates many people’s personal experiences, which can be summarised as follows: the less knowledgeable someone is, the more they overestimate their own knowledge.

The conclusions drawn from the research’s findings can have far-reaching implications:

Those who are unfit for a particular field are generally unaware of their own incompetence; in other words, they lack the ability to recognise their own inadequacy.

They are unable to distinguish between competence and incompetence, which is why they are unfit. They find it very difficult, if not impossible, to recognise their own lack of competence. This is sometimes referred to as ‘double burden’ effect, as underperformers are burdened by two factors: they lack the necessary skills, and they are not even aware of this shortcoming.

This effect leads on to the ‘Peter Principle”, which refers to the phenomenon whereby, within a workplace hierarchy, people are eventually promoted to positions in which they are no longer able to perform adequately, as they have reached the limits of their own competence. This will be the subject of the next post.

Highly qualified people tend to underestimate their own abilities in comparison with those of others. In this case, the source of the error is usually not a poor assessment of one’s own abilities, but rather an overly positive assessment of others’ abilities. This phenomenon is known as the ‘false consensus’, that is, the tendency to overestimate the opinions, attitudes and behaviour of others.

The ‘above-average’ effect, people generally rate their own abilities, traits and personality characteristics as above average. For example, whilst the average IQ is 100, people’s self-assessment places this average at 115.

The Dunning–Kruger effect, of course, had already been articulated by many people before. According to Charles Darwin’s put it “Ignorance breeds confidence more often than knowledge”, whilst Bertrand Russell put it this way: ‘…in the modern world, fools are certain, whilst the intelligent are full of doubt’.

Charles Bukowski put it this way: “The problem with the world is that intelligent people are full of doubts, whilst fools are full of self-confidence.”

Shakespeare: “The fool thinks himself wise, but the wise man considers himself a fool.”

George Bernard Shaw: “He knows nothing; yet he thinks he knows everything. This clearly refers to a political career.”

Lao Tzu: “The best thing is to know that you do not know. To think you know when you do not is a disease. If we recognise this disease as a disease, it means we can rid ourselves of it.”

Voltaire: “He must be very ignorant, because he answers every question.”

Daniel J. Boorstin: “The greatest enemy of knowledge is not ignorance, but the illusion of knowledge.”

The Dunning-Kruger effect in 2000 IgNobel Prizein the psychology category.

This recognition also went a long way towards making the Dunning-Kruger effect more widely known; today, it has become a very frequently cited principle. For example, it provides one of the most credible explanations for many of the decisions made by the American bleached-blond madman, President Trump.

Although the pair who devised the DKE had already received the Ig Nobel Prize back in 2000, the world premiere of the mini-opera on the Dunning-Kruger effect took place at the 2017 award ceremony. Here is a historic video of the opera’s stirring finale: the “The Dunning Kruger Song”:

Similar posts can be found on ‘Interesting Stories’ tag:

improbable.com: New, Added Acclaim for the Dunning-Kruger Effect
Wikipedia: Dunning–Kruger effect
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