The Dunning-Kruger Effect

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Podcast Transcript

In 1999, two social psychologists, David Dunning and Justin Kruger,  published a seminal paper on a cognitive bias that can affect nearly everyone. 

Since the paper was published, it has given a name to something which most people have recognized and, at times, may have been guilty of themselves.

However, most people who are familiar with the effect only know half the story. 

Learn more about the Dunning-Kruger Effect, what it is, and how to avoid it on this episode of Everything Everywhere Daily.

This entire episode has its genesis in a single paper written in 1999 in the  Journal of Economic Psychology.

The paper was written by David Dunning of Cornell University and his then graduate student, Justin Kruger. The paper was titled, “Unskilled and unaware of it: how difficulties in recognizing one’s own incompetence lead to inflated self-assessments.”

The paper starts with an interesting story about a bank robbery. On January 6, 1995, the would be robbers McArthur Wheeler and Clifton Earl Johnson, walked into two banks in the middle of the day, and robbed them at gunpoint, walking away with $5,200.

Neither robber appeared to have made any attempt at concealing their identity. 

The entire robbery was caught by a surveillance camera, the footage was shown on the nightly news, and both men were easily caught an hour later. 

When they were arrested, McArthur Wheeler reportedly said, “But I wore the lemon juice. I wore the lemon juice.”

It seemed that the robbers thought that if they rubbed lemon juice on their faces, it would prevent their images from being captured on camera.

Believe it or not, the robbers were not from Florida but were, in fact, from Pittsburgh. 

This story isn’t meant to illustrate a couple of guys who did something stupid. It was that they knew so little, and they were confident that what they were doing was going to work. 

What Dunning and Kruger were trying to illustrate was known as  metacognition. It wasn’t what you know but what you know about what you know. 

In the paper, they ran several tests with university students on multiple subjects, including grammar, logic, and sense of humor. The students were then ranked by their ability in each subject. 

However, the test subjects were then asked how they thought they fared.  

The people in the lowest quartile of performance believed that they had scored about 60 percent, but on average, they scored 38.4 percent. 

The people in the middle quartiles thought they scored, on average, 72.6 percent but actually scored 61.7 percent.

The people in the top quartile thought they scored 75.6 percent but actually scored 84.1 percent.

Every time this was tested, using different subjects and different tests, they found a similar pattern. The worse someone performed, the better they thought they actually did. 

This is the crux of the Dunning-Kruger Effect. The less knowledge or aptitude someone has on a subject, the more they overestimate their actual performance. Or as it states in the original paper, “incompetent individuals…will dramatically overestimate their ability and performance relative to objective criteria.”

The paper states that the reason for this is that those who lack knowledge or experience in a subject suffer a double burden. They don’t have enough knowledge or experience to know just how bad they are. 

This is not a general knowledge effect. This applies to specific applications of knowledge and expertise. 

The Dunning-Kruger Effect can be found all over, including in you and me. 

Here are some examples:

95% of American drivers think that they are in the top 50% of all drivers. 

A poll of faculty at the University of Nebraska found that 68% of professors believed themselves to be among the top 25% in terms of their ability to teach, and 90% reported themselves to be above average.

In another survey, 42% of software engineers rated their skills as being among the top 5% of their peers.

A 2018 study in the journal Political Psychology asked over 2,000 Americans general questions about politics and civics. Again, those who knew the least were the most confident about what they knew.

The effect was even more pronounced when the questions were asked in a partisan framework. The more partisan people were, the greater the Dunning-Kruger Effect became. 

Why does this so consistently happen?

For the answer to this, I’ll refer to a famous 2002 press conference given by the former US Secretary of Defense, Donald Rumsfeld. 

In it, he said, Reports that say that something hasn’t happened are always interesting to me because, as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say, we know there are some things we do not know. But there are also unknown unknowns—the ones we don’t know, we don’t know.

On this particular point, he was right. There are things we know we don’t know and things we don’t know we don’t know. 

Let’s say someone begins to learn a subject and then takes an introductory class on it. 

Their knowledge of it went from close to nothing to now knowing something. Now that they know something, they might feel that they know quite a bit about the subject.

However, they’ve only been exposed to what they know. There is still an enormous amount of knowledge that they don’t even know that they don’t know. 

The more you study, the more you become aware of exactly how big the field is and how much you still aren’t aware of. Unknown unknowns are being turned into known unknowns. 

Finally, after years of study, the known unknowns are turned into known knowns.

The problem with the novice is that they don’t know enough to know that they don’t know enough. 

If this all sounds sort of confusing, that goes back to the nature of metacognition. It is thinking about thinking or knowing what you know. 

Years ago, I wrote an article about my travels around the world that touched on this subject. The article was titled “The More I travel, the Dumber I Get.” 

The premise wasn’t that I was losing knowledge or reversing my intelligence. Instead, it was the more I traveled, the more I became aware of just how much I didn’t know. Even though I was learning quite a bit by traveling around the world, the knowledge of what I didn’t know grew at an even more rapid rate. 

One example of this occurred when I was in Singapore. While I was exploring Singapore, I encountered the Peranakan people. I had never heard of the Peranakans before. I had no idea that they existed. I’m guessing that many of you listening to this have never heard of them either. 

The Peranakans are a hybrid culture that developed when Chinese traders sailed to Southeast Asia and took Malay or Indonesian wives. They converted to Islam and created a new culture that took elements from Chinese and local cultures and created distinct foods and clothing. 

Now that I knew about this group, the floodgates opened for what I didn’t know about them. 

When did this happen? What does their food taste like? Who were some famous Peranakans? 

For anyone who listens to this podcast, you should never assume you know everything there is to know about a subject because you listened to an episode. This is a daily podcast, and there is always a great deal I have to leave out.

The Dunning-Kruger Effect actually affects everyone at some point about something. The only way to really counter it is to show intellectual humility and be willing to say “I don’t know”, or recognize that there is probably a lot about a subject that you might not have been exposed to.

I’m given suggestions for episodes of this podcast all the time by people. Many times their suggestions are good ideas, but I have to put them aside because I just don’t know enough about the topic to do a full episode on it yet. 

The Dunning-Kruger Effect is often reflected in a graph of confidence vs. competence. What it shows is a high spike in confidence with very low competence, which then drops the more competent you become and then finally increases once you’ve achieved true mastery. 

The initial peak in the graph is often referred to as “Mount Stupid.”

Everything I’ve mentioned so far addresses the traditional Dunning-Kruger Effect. That being people of low ability overestimating their ability.

However, that is only half the story. If you remember, when I gave the statistics published in the original paper, people at the very top who actually did show competence underestimated their ability. 

This is a part of the Dunning-Kruger Effect, but you probably know it better as “imposter syndrome.”

People who are knowledgeable and competent in a subject also have the skills to evaluate competence in the subject, not just in themselves, but they can see real talent in others. 

Also, they assume that if they are good at something, then surely others must be just as good as they are. 

Combined, these two parts of the Dunning-Kruger Effect can be devastating. The people who know the least are the most confident, and the people who actually know something often have little confidence. 

There have been many psychological experiments that haven’t withstood replication by other researchers. The Dunning-Kruger Effect is one which has been repeatedly demonstrated over and over. 

It isn’t a new phenomenon. It is one that has probably been around for thousands of years. As Charles Darwin summarized the Dunning-Kruger Effect over 150 years ago in his book “The Descent of Man” by noting, “Ignorance more frequently begets confidence than does knowledge.”