A little knowledge is a dangerous thing. Those who have the slightest bit of experience think they know it all. Then, with increasing experience, people realize how little they do know, how modest their skills are. Perceptions reach a minimum then slant upward again. Those at the level of genius recognize their talent, though tend to lack the supreme confidence of the ignoramus.
Coined in 1999 by the psychologists David Dunning and Justin Kruger, The Dunning-Kruger Effect is a cognitive bias whereby people who are incompetent at something are unable to recognize their own incompetence. And not only do they fail to recognize their incompetence, they’re also likely to feel confident that they actually are competent.
The irony of the Dunning-Kruger Effect is that, the knowledge and intelligence that are required to be good at a task are often the same qualities needed to recognize that one is not good at that task—and if one lacks such knowledge and intelligence, one remains ignorant that one is not good at that task.
Now, this isn’t hopeless. Professor Dunning says that one of the problems in many organizations is that many people are underperforming simply because they don’t know that they could be doing better or what really great performance looks like. It’s not that they’re necessarily being defensive, rather they just lack the knowledge.
Summing-up: The Dunning-Kruger effect is not a pathological condition. It is the human condition. You need skill and knowledge to judge how skilled and knowledgeable you are.