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What is the Dunning-Kruger effect?

Reviewed by Stephanie Steinman, PhD, CSAC

The Dunning-Kruger effect is a type of bias where the less you know about a topic, the more you think you know. Learn to identify and change this behavior.

The Dunning-Kruger effect is a type of cognitive bias in which we overestimate our abilities in areas we know little about. Essentially it states that the more incompetent someone is, the less aware they are of their own incompetence.

This bias was identified in a late 1990s study by psychologists David Dunning and Justin Kruger, who asked 65 participants to take a test measuring their logic, grammar, and sense of humor, then rate their own perception of their skills.1 Those who scored lowest in skill showed the biggest gap between their actual score and their predicted score.

Examples of the Dunning-Kruger effect

  • Someone without government or public service experience believing they’d be a highly effective elected representative
  • A student interrupting and challenging their professor throughout lectures despite not having read the required material
  • Someone from a privileged social group feeling qualified to speak on behalf of a marginalized social group despite lacking shared experiences
  • A heckler believing they’d be more entertaining onstage than the professional entertainer they paid to see

What causes the Dunning-Kruger effect?

The Dunning-Kruger effect is the result of overconfidence combined with a lack of “metacognition,” or our awareness and understanding of our thought processes and patterns.

Many of us believe incorrectly that the knowledge we have is applicable elsewhere, or that we can pick up new skills and understand new information more easily than is realistic.2 Our desire to prove that we can “keep up” may also tempt us to overestimate our competence in new or unfamiliar areas.

The four stages of competence

Also called “the hierarchy of competence,” these four stages describe our learning process in terms of our awareness and competence.

  1. Unconscious incompetence: You’re ignorant of what you don’t know.
  2. Conscious incompetence: You’re aware of what you don’t know, but you haven’t taken steps to learn more.
  3. Conscious competence: You’re actively learning and acquiring knowledge about a subject.
  4. Unconscious competence: You’ve mastered a subject so extensively that you may forget or take for granted how much you truly know.

The Dunning-Kruger effect is strongest when we’re in the first stage, unconscious incompetence. If we don’t know what we don’t know, the Dunning-Kruger effect says, then we’re actually more likely to feel confident than others at higher stages of competence. This is protective in some ways, but it can have consequences.

Who’s most likely to have the Dunning-Kruger effect?

The Dunning-Kruger effect applies to everyone. We all have major gaps in our skills or areas of knowledge, and we’re all susceptible to cognitive bias.

The Dunning-Kruger effect vs. imposter syndrome

The Dunning-Kruger effect and imposter syndrome are inverses of each other. If you have imposter syndrome, you’ve likely achieved high levels of success, mastered a skill, or know a great deal about a particular topic, but you still doubt your abilities. You may even feel like a fraud despite the amount of evidence to the contrary. This is the opposite of the Dunning-Kruger effect, in which someone has little or no knowledge but feels very confident in their abilities.

What are cognitive biases?

Cognitive biases are shortcuts in our decision-making that we take all the time without knowing it. Although they’re often illogical, they affect the way we perceive things and move through the world.

We like to believe we make decisions and observations based only on facts and truth, but most of us are actually influenced by a mixture of biases, influences, instincts, and emotions, as well as (or even despite) hard facts.

In addition to the Dunning-Kruger effect, common cognitive biases include:

  • Actor-observer bias: Attributing your own actions to external factors (“I didn’t turn in my homework because my laptop failed”) while attributing others’ to internal factors (“My classmate didn’t turn in their homework because they’re lazy”)
  • Anchoring effect: Being overly influenced by “firsts”: first impressions, first pieces of information, first offers, etc.
  • Availability bias: Using examples that easily come to mind for your decision-making, and as a result giving popular or commonly repeated data more influence than it should have (such as avoiding air travel after reading several news reports about plane crashes,even though your risk of dying in a car accident is much higher)
  • Bandwagon effect: Adopting certain thoughts, feelings, beliefs, or actions to go along with a larger group (also called “herd mentality” or “groupthink”)
  • Confirmation bias: Favoring information that supports your current beliefs
  • Loss aversion: Feeling more pain from loss than pleasure from gain (such as noticing when gas prices increase but not when they decrease)
  • Narrative bias: Interpreting the world through a particular story, even when the details aren’t related or don’t fit the ultimate narrative (for instance, believing your boss will fire you when they unexpectedly request a meeting, despite the fact that you’re an excellent employee)
  • Self-serving bias: Attributing your successes to yourself while assigning the blame for your failures to external factors (for example, believing that your good test grade was due to your intelligence and skill while a bad test grade resulted from a lack of sleep, unfair questions, and so on)

How to overcome cognitive biases

Cognitive biases like the Dunning-Kruger effect can make decision-making feel simpler and more obvious. But these biases can also get in the way of more nuanced thinking, especially when it comes to complex decisions.

Here are some ways to challenge your cognitive biases so you can overcome them:

  • Begin with data. Facts alone won’t always defeat cognitive biases, but they’re a good place to start. By searching for evidence-supported information, you’re at least admitting you don’t know everything.
  • Widen your scope. Cognitive biases can affect your learning process. Resist your biases by widening your scope and looking specifically for arguments against what you already believe.
  • Investigate your emotions. Be honest about your emotional state when you make decisions. Is this a run-of-the-mill choice, or will it have serious effects on your life? Your feelings may sway your decision one way or another. By investigating your emotions, you can be aware of and honest about how your feelings and desires may affect your choice.
  • Ask for feedback. As you start to develop a position or make a decision, ask trusted friends what they think. They may help you see information from a different perspective. If possible, seek feedback from experts whose views differ from yours.
  • Value learning. You may feel ashamed of what you don’t know. By identifying learning as a value, you can remind yourself that learning isn’t a weakness, but a strength.
  • Embrace the idea that you might be wrong. Even after a long, thoughtful process, you may still arrive at a wrong or unhelpful conclusion. That’s okay. Accept the fact that you may not get every choice right—and even after you settle on a decision, stay open to the idea of change.
  • Seek therapy. Biased or harmful beliefs are often at the root of unwanted behaviors. Some forms of therapy, such as cognitive behavioral therapy (CBT), focus on identifying and changing unhelpful biases. Browse our directory to find a licensed provider near you.

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