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The Dunning-Kruger Effect: When Unskilled People Overestimate Themselves

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Are we all prone to overestimating our abilities? The Dunning-Kruger effect, or “overconfidence in oneself”, is a very well-known principle. It can be both detrimental to the company and difficult to manage. After all, who has never had to deal with a manager or colleague that was incompetent but convinced otherwise? This phenomenon can cause tension, disrupt teams or the progress of a project, impact productivity and wellbeing at work or even be the cause of bad choices in key positions. That is why learning to recognise this bias and knowing how to fix it is essential for managers. The Dunning-Kruger effect.

What Is The Dunning-Kruger Effect?

A Cultural Cognitive Bias

This is the principle by which unskilled people believe they are skilled, that is they overestimate their abilities and performance. In terms of management, the Dunning-Kruger effect refers to those inefficient colleagues who are, nevertheless, very self-assured.

This theory, first put forward in 1999 in the Journal of Personality and Social Psychology in an article entitled: “Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments”, was developed by the Americans Dunning and Kruger, two psychology professors at Cornell University.

And all this because of a lemon!

The psychologists studied this cognitive bias consisting of the inability to objectively recognise one’s own incompetence following a news item in 1995: the robbery of two banks by a certain McArthur Wheeler, in broad daylight and with his face uncovered, yet covered in lemon juice…

The thief had been under the misconception that, like invisible ink, the lemon would make him invisible to security cameras. Dunning and Kruger have conducted several studies to understand why incompetent people can be persuaded that their poor decisions are good.

“Ignorance more frequently begets confidence than does knowledge.” Darwin


The studies were conducted on 65 western students who answered several questionnaires on the following topics:

  • humour,
  • logical meaning,
  • knowledge of grammar.

The results confirmed Darwin’s affirmation, according to which “ignorance more frequently begets confidence than does knowledge.” Their experiments showed that the least skilled people overestimated their abilities (their abilities had previously been objectively assessed by teachers), while the most skilled people tended to underestimate themselves.

What Are The Consequences of the Dunning-Kruger Effect in Business?

Of course, the difference of perception between one’s skill level and one’s actual skills has a direct impact on the relationship between employees and productivity. In the world of business, people who believe themselves to be more competent than they really are can have very harmful consequences:

  • Recruiting candidates who seem very confident but who are actually relatively unskilled;
  • Pay rises and promotions for employees who are not at the top of their game, inevitably causing a feeling of injustice;
  • Deterioration of the atmosphere within a team or department;
  • Tension and conflict which could cause stress and reduce efficiency;
  • A negative impact on work in groups, projects and achieving objectives;
  • Harmful impacts on relationships between clients and service providers.

How Can The Dunning-Kruger Effect Be Remedied?

In the face of this reality, managers must not only learn to spot the Dunning-Kruger effect, that is not to confuse self-confidence and competence, but also to manage the phenomenon and prevent its negative impacts.

Use Soft Skills

Adapting how you manage teams by using soft skills is fundamental. With this in mind, EDHEC Business School guarantees both distance and face-to-face individual and group coaching sessions as part of professional training for managers and directors.

Article: “Developing Your Soft Skills to Make a Difference in Business”

This enhanced support helps managers and future directors participating in the entirely online Manager Programme or Blended Learning to hone these essential qualities and learn to manage interpersonal relationships well.

After all, management methods play a key role. In an interview for Forbes Magazine between Mark Murphy, the founder of the Leadership IQ consultancy, and Professor Dunning, the latter explained that the main reason why some employees underperform at companies is that they do not know that it is possible to do better or recognise good results.

This means that what is taken to be the Dunning-Kruger effect can sometimes simply come down to a management problem that leaves employees in the dark.

Five Practical Solutions

There are different ways to control the Dunning-Kruger effect and manage people who overestimate their skills and struggle to question themselves:

  • Giving teams and employees regular feedback;
  • Helping them to identify their shortcomings by using specific examples to show them their failures and lead them to correct them;
  • Showing how other solutions can be more efficient and adapted;
  • Asking them to improve a specific area and encouraging them to make progress;
  • Offering training and support to develop their skills.

Developing interpersonal skills is an essential element of successfully controlling the impacts of the Dunning-Kruger effect for managers.

Article for further reading: “Team Management Training: Where To Begin”

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