Why do we fail to accurately gauge our own abilities?

The 

Dunning–Kruger Effect

, explained.
Bias

What is the Dunning-Kruger Effect?

The Dunning-Kruger effect occurs when a person’s lack of knowledge and skill in a certain area causes them to overestimate their own competence. By contrast, this effect also drives those who excel in a given area to think the task is simple for everyone, leading them to underestimate their abilities. In the years following the first description of this phenomenon, controversy has surrounded the Dunning-Kruger effect and its validity. While it was once considered a well-founded explanation of how we evaluate our abilities, the effect has since been questioned by certain data scientists and mathematicians alike.

Dunning-Kruger Effect Illustration by The Decision Lab. An orange line graph with the X axis as Competence and Y axis as Confidence. A stick man in the middle of the graph is shown with an arrow pointing towards it and the label "average person" on top of the arrow.

Where this bias occurs

Imagine you and your friend decide to try something new: separately, you both start learning Spanish. Within a few days, you can say 10–15 sentences. You’re a bit disappointed, and believe you should be able to say more by now. The language comes naturally to you, and having a good grip on it yourself causes you to think it is simple for everyone.

Your friend, on the other hand, has learned just a few words. He is amazed by his progress. He doesn’t yet have the knowledge and skills to know that he’s pronouncing those words incorrectly and forming grammatically incorrect sentences. He’s learned much less than you, but his minimal knowledge prevents him from understanding his mistakes. Moreover, his lack of comparison causes him to overestimate his relative ability. His ignorance of how far others have come (like you, for example) keeps him thinking he’s excelling when he’s actually learning at below-average speed.

Sources

  1. After Skool. (2019, October 1). The Dunning-Kruger Effect - Cognitive Bias - Why Incompetent People Think They Are Competent [Video]. YouTube. https://www.youtube.com/watch?v=y50i1bI2uN4&ab_channel=AfterSkool
  2. Jarry, J. (2020, December 17). The Dunning-Kruger effect is probably not real. Office for Science and Society. https://www.mcgill.ca/oss/article/critical-thinking/dunning-kruger-effect-probably-not-realhttps://www.mcgill.ca/oss/article/critical-thinking/dunning-kruger-effect-probably-not-real?fbclid=IwAR13aDSHXbp-X5vsEoOOxLLsQbKNpxt77CnIqto5TllpIdoRehSOK4cRW1Q
  3. Kruger, J., & Dunning, D. (1999). Unskilled and unaware of it: How difficulties in recognizing one's own incompetence lead to inflated self-assessments. Journal of Personality and Social Psychology, 77(6), 1121-1134. https://doi.org/10.1037/0022-3514.77.6.1121
  4. Macmillan Learning. (2017, November 30). Why ignorance fails to recognize itself [Video]. YouTube. https://www.youtube.com/watch?v=ErkhYq13VVE&ab_channel=MacmillanLearning
  5. Murphy, M. (2017, January 24). The Dunning-Kruger Effect Shows Why Some People Think They're Great Even When Their Work Is Terrible. Forbes. https://www.forbes.com/sites/markmurphy/2017/01/24/the-dunning-kruger-effect-shows-why-some-people-think-theyre-great-even-when-their-work-is-terrible/?sh=23923d575d7c
  6. Ted-Ed. (2017, November 9). Why incompetent people think they're amazing - David Dunning [Video]. YouTube. https://www.youtube.com/watch?v=pOLmD_WVY-E&ab_channel=TED-Ed
  7. Gaze, E. C. (2023, May 23). The dunning-kruger effect isn’t what you think it is. Scientific American. https://www.scientificamerican.com/article/the-dunning-kruger-effect-isnt-what-you-think-it-is/#:~:text=The%20Dunning%20and%20Kruger%20experiment,gauge%20their%20competence%20and%20knowledge. 
  8. Brown, J. D. (2011). Understanding the better than average effect. Personality and Social Psychology Bulletin, 38(2), 209–219. https://doi.org/10.1177/0146167211432763 
  9. Krueger, J., & Mueller, R. A. (2002). Unskilled, unaware, or both? the better-than-average heuristic and statistical regression predict errors in estimates of own performance. Journal of Personality and Social Psychology, 82(2), 180–188. https://doi.org/10.1037/0022-3514.82.2.180 
  10. FOUR STAGES CITATION (webmd?)
  11. Cherry, K. (2023, April 6). An overview of the Dunning-Kruger effect. Verywell Mind.https://www.verywellmind.com/an-overview-of-the-dunning-kruger-effect-4160740

About the Authors

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Dan Pilat

Dan is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. Dan has a background in organizational decision making, with a BComm in Decision & Information Systems from McGill University. He has worked on enterprise-level behavioral architecture at TD Securities and BMO Capital Markets, where he advised management on the implementation of systems processing billions of dollars per week. Driven by an appetite for the latest in technology, Dan created a course on business intelligence and lectured at McGill University, and has applied behavioral science to topics such as augmented and virtual reality.

A smiling man stands in an office, wearing a dark blazer and black shirt, with plants and glass-walled rooms in the background.

Dr. Sekoul Krastev

Sekoul is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. A decision scientist with a PhD in Decision Neuroscience from McGill University, Sekoul's work has been featured in peer-reviewed journals and has been presented at conferences around the world. Sekoul previously advised management on innovation and engagement strategy at The Boston Consulting Group as well as on online media strategy at Google. He has a deep interest in the applications of behavioral science to new technology and has published on these topics in places such as the Huffington Post and Strategy & Business.

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