The Dunning–Kruger effect is not what the internet says
It started with a bank robber who thought lemon juice made him invisible. The famous “Mount Stupid” chart was never in the paper.
In 1995 McArthur Wheeler robbed two Pittsburgh banks without a disguise. He had rubbed lemon juice on his face, believing it would make him invisible to cameras (lemon juice can be used as invisible ink, so he reasoned it would work). When police showed him the footage, he was reportedly astonished.
The psychologist David Dunning read about the case and wondered whether lacking a skill also means lacking the ability to notice that you lack it.
What the study found
Dunning and his student Justin Kruger tested people on logical reasoning, grammar and humour, then asked them to estimate how well they’d done. People in the bottom quarter, who scored around the 12th percentile, estimated they were around the 60th. Top performers slightly underestimated themselves.
What the internet added
The popular chart, with a spike of confidence at “Mount Stupid”, a “Valley of Despair” and a slow climb to expertise, does not appear in the paper. In the actual data, low performers still rated themselves below high performers. They were overconfident, but not more confident than experts.
Bring it up
“The Dunning–Kruger paper was inspired by a man who robbed banks with lemon juice on his face, believing it made him invisible to cameras.”
Follow the thread
- RelatedAI has gone through “winters” before Experts can be strikingly overconfident about problems they haven’t yet solved.
- RelatedWhen a measure becomes a target Both are about the gap between how we measure ourselves and how things really are.
- RelatedOnce you notice something, it’s everywhere Another cognitive bias that the internet loves to cite, and sometimes cites imprecisely.
- RelatedDoes listening to Mozart make you smarter? Another psychology result that is repeated far more confidently than the evidence supports.
- RelatedThe doctor who said “wash your hands” Experts can be blind to their own errors, especially when the error implicates them.
- In contrastThe man who decided the missiles weren’t real Good judgement can mean being sceptical of a confident-looking signal.
