The Dunning Kruger Effect & Threshold Concepts: Why You Have No Idea What You Do or Don’t Know

If you know anything about the Dunning-Kruger Effect, you’ll know the story of McArthur Wheeler, a man who robbed banks and believed he had evaded the security cameras’ tracking eyes by dousing himself in lemon juice.

Tim Harford does an excellent job, as always, of breaking down complex ideas.

This sounds ridiculous, and of course it is, but the key to this story is Wheeler’s fervent belief that he knew what he was doing. It wasn’t his ignorance that was his downfall, although that certainly helped, but instead his shocking self-assuredness. He was stunned when officers knocked on his door as he genuinely believed he’d gotten away with it.

The story of the man who robbed banks while thinking himself invisible to modern technology” exaggeratedly encapsulates what is known as the Dunning-Kruger Effect: a well-known concept in popular culture by now, so I will spare you the details of it. Feel free to research and read up on it, but the gist of it is this: a study conducted by two social scientists apparently supported the idea that people of low ability overestimate their own abilities while people of high ability overestimate others’ abilities.

What this means in practical terms is that when you’re bad at something, truly bad, then you really have no idea that you’re quite as bad as you are: you don’t know what you don’t know. This tends to result in an overestimation of your own abilities. On the other hand, when you’re great at something you tend to have an accurate assessment of your own abilities (ie, you do know what you know and don’t know) but you overestimate others. I like this to think of this as having forgotten what you didn’t know.

While there has been mathematical critique of the results of the Dunning-Kruger study, there seems to be a clear understanding of the cognitive bias that while the truly awful may not always think they’re the best, they do tend to overestimate their abilities. Upon hearing this, most of us nod immediately because it seems like common sense: of course we aren’t good at knowing what we don’t know. However, it’s easy to grasp this concept as a theoretical construct, but nearly impossible to internalize it: Others don’t know what they don’t know is easy to grasp; telling oneself I don’t know what I don’t know is much harder. After all, it’s not a blindspot if you can see it, right?

So, what should we take away from understanding this phenomenon?

First, it applies to you.

The unfortunate mistake many make is assuming they aren’t stupid, or that intelligence or content / skill mastery is binary. Hearing tales of incompetence makes us laugh and delight in our own brilliance. However, the real point of stupid-criminal stories is not that some of us are just better than others; it’s that all of us are pretty terrible at seeing our own shortcomings. This is where intellectual humility comes into play: don’t pretend you are the only person in the world with no biases or blindspots. Acknowledge they surely must exist and allow for external feedback to inform your own metacognition: be humble.

Second, the Dunning-Kruger Effect actually says a lot about competent people.

If you search on the internet, the general understanding of the Dunning-Kruger Effect is that stupid people think they’re smart. However, the theory has just as much to say about smart, highly-skilled people — if not more. The notion of threshold concepts comes into play here.

The Meyer and Land threshold concept was originally applied to a study of economics, but has now been applied across a wide range of disciplines. A threshold concept is one that is essential to mastery of a subject and is generally defined by three prominent qualities: it is transformative, irreversible, and rooted in liminality.

Breaking these individual traits down looks like this: a threshold concept fundamentally alters one’s understanding in a way that can’t be undone (the cat can’t go back in the bag) and doesn’t happen in one fell swoop: understanding will be messy and will likely feature setbacks and points of being ‘stuck.’

The importance in understanding threshold concepts is that once you’ve grasped a concept, you likely won’t even know it. There won’t be a single EUREKA! moment where it all comes together; understanding will come as a result of a messy process that first made you feel incompetent, then like an imposter, and finally…ok.

Third, you have no idea what others know, and don’t know.

Teaching someone to ride a bike is difficult because anyone who can competently do has trouble remembering what it was like when they couldn’t; they just hop on and ride, oblivious to the seemingly countless steps involved: they just do it. This seems obvious, but how often do we assume that because we grasp something, others must have, as well? Working with others who have less mastery or skill requires us to think of the steps involved; this is why teaching something is crucial to your own understanding. Do you want to know if you really understand something? Try teaching it to someone else.

I spend hours each day learning software development. CSS frustrates the hell out of me. I spent three hours yesterday setting up my environmental variables so I could deploy a web app on Heroku. Each time I open VS Code I’m reminded of what I don't know, but I also know to appreciate how much more I know than when I set out to learn this new skill. I know so much more about JavaScript, relational databases, and HTML partial templates — but fortunately I’m old enough to have developed some basic metacognitive skills and my teaching career grounds me in the knowledge that learning isn’t linear. Mastery is a messy process that requires periods of doubt, ambivalence, and frustration. Stay humble and remember that everyone is on the same journey — some are just more aware of it than others…or at least they think they are.

A web developer with an extensive background in education who combines experience in communicating abstract concepts with a knowledge of software development to