Dunning-Kruger Effect
Metacognitive Blind Spots.
If
Lacking expertise in a domain also means lacking the meta-skill required to recognize one's own incompetence. In the original study the bottom quartile scored around the 12th percentile and placed themselves near the 60th. Top performers under-rated themselves, because they assumed others found the task as easy as they did.
Then
When someone declares a hard problem "easy," check their domain history before trusting the estimate. During scoping, pair confident newcomers with quiet veterans and weight the quiet voice.
Unless
Calibrated Confidence — the effect is contested — much of the classic pattern is reproduced by regression to the mean in noisy self-assessment, so treat overconfidence as a prompt to check the record rather than as a diagnosis