The Dunning-Kruger effect: when trust defies competence

The Dunning-Kruger effect: when trust defies competence
Article Jun 13, 2025 2 minutes
  • Talent Development
PerformanSe

Have you ever met someone who seemed terribly confident in a skill they barely mastered? Or have you ever underestimated yourself in an area where you excel? These situations illustrate a universal and fascinating cognitive bias: the Dunning-Kruger effect.

The birth of a disconcerting bias

In 1999, psychologists David Dunning and Justin Kruger shed light on a fascinating mechanism in cognitive psychology. Their original study revealed a surprising paradox: the people who are least competent in a field are often those who most overestimate their abilities.

A practical example:The original test

In their inaugural study, Dunning and Kruger subjected participants to humour, grammar and logic tests. The results were edifying: the worst-performing participants systematically overestimated their abilities, and were well above the perceived average.

The stages of the Dunning-Kruger curve

  • 01.

    The summit of the mountain of stupidity

    A phase where total ignorance is accompanied by maximum confidence. The individual doesn't know that he doesn't know.

    Example: A beginner in photography who thinks he has mastered all the settings after buying a professional camera.

  • 02.

    The valley of despair

    The moment when the person realises the immensity of what they don't know. Confidence plummets in the face of the complexity of the field.

    Example: A new entrepreneur discovers the wide range of skills needed to run a business.

  • 03.

    The slope of awakening

    Competence and confidence are gradually built up in parallel. Learning becomes systematic and structured.

    Example: A developer moving from basic code to a complex software architecture.

  • 04.

    The sustainability plateau

    Confidence is finally aligned with real skills. Expertise becomes solid and measurable.

    Example: A professional who can accurately assess his or her strengths and limitations.

The metacognitive deficit: The key to explaining it

The explanation for this phenomenon lies in the metacognitive deficit. Low-competent individuals lack the necessary skills to objectively assess their own performance. It's a vicious circle: their incompetence prevents them from recognising their own incompetence.

The skills required to be an expert in a field are often identical to those needed to assess one's own expertise. An individual with low skill levels does not have the cognitive tools to accurately measure his or her shortcomings.

Beyond conventional wisdom: A statistical perspective

Recent research qualifies this interpretation. Statistical models suggest that the Dunning-Kruger effect could also be the result of mathematical phenomena, in particular :

  • Regression to the mean
  • The intrinsic constraints of performance scales
  • The natural variability of self-assessment

These models suggest that the phenomenon is not just psychological, but also linked to complex statistical mechanisms.

Personal development: The path lucidity

How can we overcome this bias? The key lies in self-reflection and continuous learning. Self-knowledge then becomes a powerful tool for progress.

Psychometric tests, such as those developed by our teams, can help with this process of introspection. By providing an objective mirror of our skills and potential, they enable us to better understand our strengths and areas for development.

Practical strategies for overcoming the Dunning-Kruger effect

  • 01

    Cultivating intellectual humility

    • Accepting that we don't know everything
    • Remaining open to new perspectives
  • 02

    Seek objective feedback

    • Get feedback from mentors
    • Take part in training courses
    • Compare skills rigorously
  • 03

    Developing metacognition

    • Practising self-observation
    • Regularly analyse your learning processes
Illustration of a compass

The Dunning-Kruger effect reminds us of the importance of intellectual humility. Acknowledging your limitations is not a weakness, but the first step towards true expertise.

Knowledge is not a state, but a journey. A journey where curiosity and open-mindedness are our best companions.

Discover your true potential!

Develop a true understanding of your soft skills through our expert assessments.
Free Trial Free Trial

Newsletter

Thank you for subscribing to our newsletter!

You’ll now receive our articles, be informed of our events and benefit from our white papers.

Ready to discover your next talents?

Complete the form to get a demo with one of our experts

Footer form

Thank you!

Your info was submitted successfully.

Attention

Please rotate your device