The Dunning–Kruger Effect: Why People Overestimate Their Skills

Oct, 2023


Are you confident about your skills and abilities?

Do you think you are better than average at what you do?

Vocabulary list 

• Students read each word followed by the definition, focusing on the correct pronunciation.

• The teacher reads the sample sentence and the students repeat, focusing on the correct pronunciation.

• After reading the list, students try to make their own example sentences using the words that are new to them. 

• Students share their example sentences and the teacher gives feedback, correcting errors if necessary.

assume (verb)


to believe that something is true or will happen, often without proof

Most people assumed Hilary Clinton was going to win the election.


inflated (adjective)


larger than what should be the normal size

David comes from a very rich family and has an inflated opinion of himself.


estimate (verb)


to guess or calculate the value, cost or amount of something

The holiday rep estimates that it will take about two hours to drive to the coast.


estimation (noun)


an opinion of something or someone

My estimation was wrong, so the job is going to take longer than I thought.


tend (verb)


to be likely to behave in a particular way or have a particular characteristic

My art teacher at school tended to give us a lot of freedom in our lessons.


distorted (verb)


to change something so that it is false or wrong

The media often distort the facts of a story to make it more newsworthy.


incompetent (adjective)


not having the necessary skills or knowledge to do something well

We could achieve more as a team if we didin’t have incompetent managers.

Dunning–Kruger Effect: Why People Overestimate Their Skills

In a Swedish study published in 1981, 93% of American drivers and 69% of Swedish drivers claimed that their driving skills were above average. This is impossible as more than 50% of people cannot be above average. Another study done in 1992 found that 42% of the engineers at a US company assumed that they were among the company’s top 5% engineers! So what is the cause of this inflated belief in one’s own abilities?

According to the research, most people are very poor at estimating their own abilities, especially people in western cultures. So in 1999, two social psychologists called David Dunning and Justin Kruger decided to investigate why. In their research study, they did four experiments that tested participants’ understanding of humour, grammar and logic. The results showed that, in general, people with the least ability had a higher estimation of their skills and abilities. Those who achieved the lowest 25% of results tended to believe that their performance was above average. Sometimes, they even believed they were in the top 40%.

The reason for this lack of personal understanding is partly down to what is called cognitive bias. This is when our perceptions and personal beliefs are distorted by our society, culture and experiences. This can have a negative influence on the way we think. Another reason is that “incompetent” people are often unable to recognise their own mistakes and lack of skill. They also fail to recognise the skill and expertise of other people.

Dunning and Kruger suggested that people who lack the awareness, skill or ability to make unbiased conclusions are likely to make poor choices. This makes them unable to realise and acknowledge their own mistakes. This combination of incompetence and overconfidence is now known as the Dunning-Kruger effect.

As a result of their research, Dunning and Kruger found that when people improve their skills and knowledge, they become better at recognising their weaknesses. Therefore, if people improve their skills, they are less likely to be affected by the Dunning-Kruger effect.



1. According to a survey, most people in Sweden have above average driving ability.



2. A research study in 1992 concluded that US engineers were in the top 5% in the world.



3. According to the text, 25% of people are very bad at estimating their abilities.



4. According to the text, the people who achieved results in the top 40% of the Dunning and Kruger test did not have an inflated opinion of their abilities.



5. According to the text, incompetent people reject the advice they get from people who are more skilled than them.



  • What do you think about the Dunning-Kruger effect?

  • Why do you think Dunning and Kruger used humour, grammar and logic to test the people in their study?

  • Is there anyone you know that you think is affected by the Dunning-Kruger effect?

  • How self-confident do you think people are in general in your culture?

  • What are the pros and cons of being self-confident?

  • Who’s the most self-confident person you know?

  • Which of your skills or abilities are you most confident in?

  • Are there any skills that you feel like you need to improve?

  • Are there any new skills that you would like to learn someday?

  • Socrates stated: The only true wisdom is in knowing you know nothing”. What do you think about this statement?