On April 19, 1995, McArthur Wheeler robbed a bank. He had rubbed lemon juice on his face, believing it would make him invisible to surveillance cameras, similar to how lemon juice can be used as invisible ink on paper. The police released the surveillance footage on the local 11 o’clock news, and he was arrested shortly after midnight. Wheeler incredulously remarked, “But I used the juice.”
Perplexed by Wheeler’s reasoning, psychologists David Dunning and Justin Kruger studied Wheeler and others like him. They concluded that people with low abilities in a task often overestimate their competence—a cognitive bias now known as the Dunning-Kruger effect.
Confidence vs. Actual Knowledge
When we start learning something new, we often feel very confident because we know so little. We might believe we understand everything. If we stop learning at this stage, we remain convinced we are experts. Those who continue to learn begin to see the complexities and often lose confidence. The more they learn, the less confident they become. Many stop at this stage, thinking they have learned nothing. Only by persevering do we regain confidence while becoming genuinely more skilled.
To illustrate, imagine a debate between a simpleton, a good student, and a wise teacher. The simpleton knows little but is very confident and speaks loudly and assertively. The student knows more but lacks confidence and remains silent. The teacher is confident but understands the complexity of the subject and speaks with caution. In the end, most people agree with the simpleton because of his apparent self-assurance. People tend to trust confidence.