In 1995, a man named McArthur Wheeler robbed two Pittsburgh
banks in broad daylight, without a mask. He’d splashed lemon juice on his face
prior to the robberies, convinced it would make him invisible to security
cameras. He was utterly dumbfounded when police showed up at his home to arrest
him. He knew you could use lemon juice to write invisible messages; obviously
the juice would make him disappear as well. When news of his misadventure
reached two psychologists at Cornell University – David Dunning and Justin
Kruger – they were fascinated. How could someone be so certain, yet so wrong? Four
years later the pair released a study describing the Dunning-Kruger effect:
those of us who know the least often convince themselves they know the most.
The less we know, the smarter we feel. And the more we learn, the more we realize
how much we don’t know.

















































