Dunning-Kruger Effect

What it means

The Dunning-Kruger effect is the cognitive bias where people with limited knowledge or skill in a domain significantly overestimate their own competence. At the same time, genuine experts tend to underestimate theirs. The gap between what people think they know and what they actually know is widest when they know the least.

This happens because competence and the ability to assess competence require the same underlying knowledge. If you don’t know much about epidemiology, you also don’t know enough to recognise what you’re missing. The gaps in your knowledge are invisible to you. Meanwhile, an expert is acutely aware of everything they still don’t know, which makes them more hesitant.

The effect doesn’t mean uninformed people are stupid. It means they’re operating with an incomplete map and don’t yet realise how much territory the map is missing. The first step to genuine understanding is usually the humbling discovery of how much you don’t know - what psychologists sometimes call “conscious incompetence.”

In the real world

Social media has amplified the Dunning-Kruger effect dramatically. Someone who watches a few videos about a complex topic can feel sufficiently informed to argue with specialists. During the pandemic, this played out at enormous scale - people with no medical training felt confident enough to dismiss consensus medical advice.

In the workplace, it shows up in meetings where the person with the strongest opinion is often the one who has engaged least deeply with the problem. The people closest to the work are more likely to hedge, qualify, and express uncertainty - which paradoxically makes them less persuasive.