Dunning-Kruger Cognitive Bias

As we first addressed in our posting Standing In Midair, cognitive bias is a limitation in our ability to think objectively.  When you see a person materially overestimate their ability, the Dunning-Kruger Cognitive Bias is quite likely the cause.  Somewhat surprisingly, this cognitive bias is also the likely cause when a person materially underestimates their ability.  Social Psychologists, David Dunning, and Justin Kruger identified the illusion of superiority as a cognitive bias in their study “Unskilled and Unaware of It: How Difficulties in Recognizing One’s Own Incompetence Lead to Inflated Self-Assessments” (1999).


This first version of this bias results in a twofold effect.  A person who is incompetent at something fails to see their incompetence.  Then the person more often than not mistakenly believes they actually are competent, thus significantly overestimating their competence.

Dunning and Kruger administered a grammar test to Cornell undergraduates.  Then they asked the participants how well they believed they had performed.  The poorest performing participants scored in the 10th percentile, i.e., worse than 90% of all participants.  However, in their performance estimates, they anticipated scoring in the 67th percentile or better than 2/3 of all participants.

The explanation for this disconnect is that both accurately evaluating performance and actually accomplishing the performance being evaluated require the same the intelligence, knowledge, and skills of perception.  So, poor performance is an indicator of an inability to assess performance accurately.  Failing to assess performance accurately leads to overconfidence.

To be clear, Dunning & Kruger studied the competence not the intelligence of their test subjects.  They chose that approach to address empirical facts (see our posting Empirically Yours ) of actual performance in their study rather than trying to compare other factors such as intelligence or education.

Those who experience this version of Dunning-Kruger Cognitive Bias need to conquer their overconfidence.

Lack Of Confidence

This second version of this bias is the inverse of the first version.  Those scoring the best on the tests consistently underrated their performance, i.e., the person so underestimates their competence they feel they would be judged an imposter if they were ever “found out.”  They may be quite competent in a variety of matters, exceeding their peers.  However, what they do seems easy to them, and they assume (i) it must not be difficult for others either, and (ii) since there is nothing special about what they do, it must not be particularly significant or valuable.  This mindset is also known as the “Imposter Syndrome.”

Those who experience this version of Dunning-Kruger Cognitive Bias need to overcome their lack of confidence.

Conquering Overconfidence

  • Slow Down.  In Thinking Fast & Slow author, psychologist, and Nobel laureate, Daniel Kahneman explains the functioning of our brain by describing two systems that drive it and, by extension, us.  System 1 is fast, automatic, intuitive, unconscious, typically in charge, and prone to errors.  System 2 is slow, analytical, deliberate and rational. 
    • As to cognitive biases, Kahneman says, “Because System 1 operates automatically and cannot be turned off at will, errors of intuitive thought are often difficult to prevent. Biases cannot always be avoided, because System 2 may have no clue to the error. Even when cues to likely errors are available, errors can be prevented only by the enhanced monitoring and effortful activity of System 2.” [Emphasis Added]
    • So, slowing down will give you a better chance of disengaging System 1, avoiding its impulsivity, and reducing the likelihood of falling prey to the overconfidence of the Dunning & Kruger Bias.
  • Use Your Confidence Consciously.  Confidence is a good thing when it is based upon having paid the price of entry in the form of preparation, consideration, performance, and realistic reflection on the outcome of your efforts.  Anything less is likely to be overconfidence.
  • Recognize A Little Knowledge Is A Dangerous Thing.  Once is a random event.  Twice is a coincidence.  Three times is the beginning of a pattern.  Confidence in a pattern makes sense.  Confidence in random events or coincidences does not make sense.
  • Continue Learning/Studying At All Times. What we don’t know is vastly greater than what we do know.  Learning new things continuously has two beneficial effects, apropos overconfidence.
    • First, it is a great perspective-setting-reminder of our true range of knowledge, illuminating what should be the degree of confidence we harbor.
    • Second, it leads to greater knowledge, providing a more current perspective of what we already know, and thus a clearer understanding of our true competence.

Overcoming Lack Of Confidence

  • Consider The Confidence Levels Of Others.  Remind yourself how many people suffer from a misinformed overconfidence.  Accordingly, discount your comparisons of them to you.  Remind yourself, when something seems easy for you to do, it’s because of your skill, not because it’s easy for everyone else to do what you do.
  • Develop A Beginner’s Mind.  In Zen Buddhism the term “beginner’s mind” is expressed by concept shoshin.  It refers to letting go of preconceptions and having an attitude of openness when approaching a topic, a person, an objective, etc.  This relieves the person of being the “expert” or needing conform to some set of expectations that become the basis of concerns that are at the core of a lack of confidence.  Honor Nassim Taleb’s observation in his book, Fooled By Randomness, where he says, “I try to remind my group each week that we are all idiots and know nothing, but we have the good fortune of knowing it.”


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