THE DUNNING-KRUGER EFFECT –WHY IGNORANT PEOPLE THINK THEY KNOW BEST
- Nicholas Alexander
- Jun 14, 2022
- 3 min read

A guest post by Zena Everett, author of The Crazy Busy Cure
In 1995 a bank robber in Pittsburgh called McArthur Wheeler attempted to rob two banks. His
only disguise was to smear lemon juice on his face, convinced that it would make him
invisible to security cameras. His speedy arrest intrigued social psychologists David Dunning
and Justin Kruger, who studied the case to understand how someone so hapless could be so
confident.
They asked a group of students to complete self-evaluations in three areas: humour, grammar, and logical reasoning. Then they compared the results with their actual skills.
The findings were clear: the most gifted students tended to underestimate their abilities
whereas the least able clearly overestimated themselves. This cognitive bias became the Dunning Kruger Effect: when people with limited competence greatly overestimate their ability. It’s why eight out of ten American men think they drive better than everyone else.
Don’t be fooled by the foolish
I’m a huge advocate of the growth mindset: that our abilities aren’t fixed but can be
developed with hard work. But the Dunning-Kruger bias gives power to the wrong people. It’s
downright dangerous for unqualified self-help gurus to spout health advice, or for political
leaders to make decisions with only a limited grasp of their brief.
Have you seen people talk themselves into roles that are way beyond their current capability
and don’t bother to seek advice from the skilled people around them? Or a ‘new broom’
rocking a steady boat in their first few months because they think they know better?
It must be true, I read it online
Social media gives a megaphone to the ill-informed. Fake news travels faster than facts
because it’s not burdened with detail. When you think you know it all it, you aren’t interested
in the other side to the argument, the ‘so-called expert’ one.
Meanwhile the thoughtful experts hesitate: this is the flip side of Dunning Kruger, where the
more you know, the more you realise you must learn. Experts measure themselves against
their peer group and feel they fall short. That’s why talented mid-career professionals have
confidence wobbles: they are encumbered by self-awareness.
The whole problem with the world is that the fools and fanatics are so certain of
themselves, and wiser people so full of doubts – Bertrand Russell (1951)
How to quench the Dunning-Kruger effect in your organisation
Empty vessels make the most noise. The vocal minority may not be right. Check your
facts, don’t be swayed by soundbites.
Coach managers to listen better, so they get to the heart of an issue before racing off to
make decisions without the full picture.
Praise expertise and sponsor education. Create a genuine learning environment and
encourage reflection. Cut the noise and create space to think.
See imposter syndrome and crises of confidence as opportunities for development.
They flag up that people know what they don’t know: what’s wrong with that? Help
them to fill the gaps.
Train managers to weed out over-confident candidates who mask mediocrity with
promises and excuses.
Feedback removes blind spots. Don’t safe it up for formal appraisals; train managers to
maintain a continuous feedback loop.
Don’t let people blame everyone else for mistakes. State where the buck stops and
keep everyone accountable.
Coach quieter experts on how to have more influence.
Invite people with worthwhile opinions to meetings and ensure they have their say. Stop
inviting people who speak up but add nothing.



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