What Is the Dunning-Kruger Effect?

Introduced by psychologists David Dunning and Justin Kruger in a 1999 research paper, the Dunning-Kruger effect describes when a person overestimates their knowledge or ability in a given situation and is unaware of their actual competence level.

In the Dunning-Kruger experiment, participants were asked to estimate their performance on grammar, logic, and humor tests.

After completing the tests, researchers found that those who scored lowest tended to significantly overestimate their abilities. For example, those who estimated they would score in the 62nd percentile actually scored in the 12th percentile.

The Dunning-Kruger effect is not recognized in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Instead, it’s considered a psychological phenomenon rather than a disorder.

The Dunning-Kruger effect can occur in anyone and any context, including work or educational settings and social situations. Here’s what it looks like:

• At a social gathering. A person may claim they know everything about a certain topic. But if they’re corrected by someone who has extensive knowledge, they may not take responsibility for their inaccuracies or blame external factors.

• At work. Someone who automatically assumes they’ll get a promotion because they believe they are a top performer for the company. And they’re shocked or surprised if they receive a performance review that doesn’t align with how they see themselves.

• Sports. Someone experiencing the Dunning-Kruger effect may believe they are capable of being a starter on their team, even if they haven’t spent time practicing. They may find themselves unable to recognize why others don’t perceive their performance as stellar or greater than other teammates.

The short answer to that question is maybe. Stronger evidence suggests that the Dunning-Kruger effect is a real phenomenon. But like many theories within the psychological arena, more investigations are needed to understand it better.

In addition to Dunning and Kruger’s findings, a recent study found similar results in knowledge- and skill-based tests and tests that access emotional intelligence.

But research from 2017 suggests that an individual’s self-assessment genuinely reflects their actual abilities. They also indicate that experts are more proficient in self-assessing their abilities than novices, and women may self-assess more accurately than men.

It’s important to note that most people generally aren’t good at judging their skills and abilities. A study from 2008 suggests that it can be difficult for people to self-assess due to a lack of information or bias that can help them accurately self-evaluate.

But the Dunning-Kruger effect is an important finding as it’s not common that people are unaware of how they overestimate their skills and knowledge.

Causes of the Dunning-Kruger effect aren’t well understood. Kruger and Dunning suggest that some people may overestimate their abilities because accurate self-assessment depends on the same set of skills and knowledge as performance.

But some research notes that the Dunning-Kruger effect may result from low metacognition — the ability to understand and be aware of what you know and what you don’t know.

Cognitive bias, or the tendency to align thoughts with existing beliefs, may also play a role. For instance, if someone has strong views on a topic, they may not accept scientific evidence that suggests their belief is wrong.

Anyone can experience the Dunning-Kruger effect, including experts or highly educated people. Still, individuals who tend to be less self-aware or don’t rely on critical thinking may be most impacted by this psychological phenomenon.

Problems that can arise from this effect may be mild or severe. For example, a person claiming at a dinner party to have extensive knowledge about a random topic may come across as annoying. However, this is much less impactful on others than someone who overestimates their skills in a dangerous situation.

For instance, a truck driver overestimating their ability to drive through a storm could result in an accident, or a surgeon overestimating their skills could result in patient injury.

Inaccurate self-assessment can also result in the opposite effect, known as imposter syndrome. People with this way of thinking underestimate their abilities, downplay successes, and have persistent self-doubt even though they’re highly qualified.

If you’re experiencing imposter syndrome, you may constantly feel like you’re a fraud and attribute your successes to luck or outside factors rather than competence.

Like the Dunning-Kruger effect, imposter syndrome is considered a phenomenon and not recognized as a disorder in the DSM-5.

Although you may not be able to completely avoid this phenomenon in others, there are ways to manage it if you’re exhibiting the Dunning-Kruger effect, such as:

• Continually ask yourself, do I really know enough about this, or could I learn more?
• Avoid assuming your skills always match the task at hand.
• Ask for and be willing to accept honest feedback from friends, family, or co-workers.
• Question your own beliefs to determine whether they’re impacting your ability to self-assess your knowledge or skills.

If you believe you know someone who is exhibiting the Dunning-Kruger effect, you could consider:

• Avoiding debate or arguments with the person unless necessary, as they genuinely believe they are experts.
• Exercising empathy and realizing their overinflated competence is most likely stemming from deeply rooted personal challenges.
• Realizing their comments and behaviors have nothing to do with you, and they are often unaware of their shortcomings.
• Offering them the educational resources needed to increase their knowledge and abilities so they are more in line with their self-assessments.

The Dunning-Kruger effect describes someone who inaccurately assesses their knowledge and skills and believes their competence level far exceeds their actual abilities. It can impact personal and professional relationships and occurs across various domains, from social situations to workplaces.

People who experience this psychological phenomenon may lack self-awareness, have reduced metacognition, exhibit cognitive bias, and may not be aware of their inadequacies. But more research is needed.

If you are dealing with someone exhibiting Dunning-Kruger-related behaviors, it’s helpful to know that their thoughts and actions stem from their own challenges and have nothing to do with you and your abilities.

But if you think you may be the person experiencing the Dunning-Kruger effect, there are ways to manage it.

First, you could determine areas in your life you may not be as knowledgeable as you believe. You could then work toward accepting constructive criticism, feedback, and knowledge from others to better align your skills with your self-assessed competence level.