Have you ever heard of the knowledge curve? Also called the learning curve, it is closely tied to a well-known psychological effect: the Dunning-Kruger effect.
It is a cognitive bias, well known in psychology, which explains why the least competent people in a field tend to overestimate their abilities, while the most competent tend to slightly underestimate their own level.
Online, this effect is often shown with the curve below. Yet it doesn't come from the study: Dunning and Kruger never drew this peak followed by a dip.
As you can see, this curve tells the story of learning in three stages:
- A stage of illusory competence;
- A stage of despair;
- A stage of growing competence.
In this article, we'll look at what the 1999 study really showed, how this effect shapes the way we learn and perceive our skills, and why it is essential to understand it in order to grow.
The origins of the Dunning-Kruger effect
In 1999, David Dunning and Justin Kruger, two researchers at Cornell University, published their study on this psychological bias. According to it, people with little skill in a field are often unable to recognize their own incompetence.
This leads them to overestimate their abilities and to become overconfident.
What the study actually measured
In practice, the two researchers gave students tests of humor, logic and grammar, then asked them to estimate how many participants they had outperformed.
The bottom quarter scored, on average, in the 12th percentile: in other words, they outperformed only 12% of participants. Yet they placed themselves in the 62nd percentile.
The top performers, for their part, slightly underestimated themselves: what felt easy to them, they assumed was easy for everyone. Once shown other participants' answers, they revised their self-assessment upward. The weakest performers, on the other hand, did not.
Finally, in a last experiment, a short training session in logic was enough for the weakest participants to judge their own performance better and lower their estimates: getting better makes you more clear-sighted.
In other words, the least skilled people overestimate themselves the most, while the most competent tend to slightly underestimate themselves. 😗
This phenomenon is often summed up by a line from the naturalist Charles Darwin, in The Descent of Man (1871): "Ignorance more frequently begets confidence than does knowledge."
Source: Justin Kruger and David Dunning, "Unskilled and unaware of it", Journal of Personality and Social Psychology, vol. 77, no. 6, 1999, pp. 1121-1134.
The stages of the knowledge curve
The curve we saw in the introduction breaks learning down into three stages. It doesn't come from the study, but many learners recognize themselves in it.
The stage of illusory competence
To begin with, the learner has inflated confidence at the very start: when they begin learning a subject, they pick up a few basics fairly quickly and think they have already mastered it. This is called the illusion stage.
Confidence is at its peak, while actual competence is still very low. People feel they have understood everything, when they have only mastered a tiny part of the subject.
Example: Imagine a student who has just started learning to code. After a few courses, they can write simple loops and conditions, and they feel ready to build an entire application.
They don't yet see how complex algorithms are, or the optimizations needed to make their site usable: this is the stage most people fall into. 😉
The stage of despair
Then, faced with evidence of their incompetence, the learner moves into another stage: disillusionment (also called the stage of lost confidence, or of despair). As they dig deeper into the subject, they realize how complex it really is.
This is when confidence drops sharply. It is also the stage where most people give up, convinced they will never make it.
Example: The programming student starts discovering advanced concepts such as data structures, databases and object-oriented programming. They feel overwhelmed and doubt they will ever truly master the subject.
The stage of growth
Finally, they reach the stage of growing competence: as their skills improve, they gradually regain confidence in their abilities.
At this point, people become aware of what they know and what they don't, which lets them assess their skills more accurately.
Example: After months (or years 🥲) of practice, the programming student can understand advanced concepts and apply their knowledge effectively. They are confident, but still aware that there is always more to learn.
Examples of the Dunning-Kruger effect
Beyond our programming student, let's look at other everyday situations where this psychological bias is very much present (you may even have experienced it yourself).
Example 1: Learning to drive
Do you remember your first hour behind the wheel? Many people think they already know how to drive before they have even touched the steering wheel!
Of course, thirty hours of driving later, many have gone through every stage of the Dunning-Kruger effect: from overconfidence to despair, wanting to give up and believing they will never be able to drive on the highway, all the way to getting their driver's license.
Example 2: Learning a new language
It's no coincidence that apps that help you master a language are thriving, and that they do everything they can to keep us hooked at the start: the Dunning-Kruger effect is very much at play.
At first, a well-designed app can make it feel like "it's easy".
It isn't.
Only after a few lessons do most learners give up, faced with how much there is to learn.
Finally, after months of sticking with it, they manage to speak the language fluently while being aware of what they still don't know.
How can you avoid the Dunning-Kruger effect?
This cognitive bias is not easy to avoid. In fact, the key is to stay humble and keep learning actively (without letting it throw you off).
Generally speaking, our learners manage to counter this effect with a few simple habits:
- Be aware of your limits: accept that you can't know everything, and be ready to listen to people with more experience than you;
- Step back: always test and validate your knowledge with outside feedback (from mentors or experts) before considering yourself fully competent;
- Adopt a lifelong learning mindset: even the greatest experts never stop learning. There is no point at which you will "know everything there is to know".
Conclusion
The Dunning-Kruger effect reminds us of the importance of humility in our everyday learning.
This knowledge curve is not a finding of the study, but it does illustrate the path we all travel when we learn something new.
Becoming aware of this effect, recognizing your own limits and persevering through moments of doubt are essential to growing, whether at work or in everyday life.
The next time you feel too sure of yourself in a field, or on the contrary overwhelmed, remember the Dunning-Kruger effect and keep learning! 😬