Dunning-Kruger Effect

In 1999, David Dunning and Justin Kruger at Cornell University published research demonstrating that people with limited knowledge in a domain dramatically overestimate their competence, while genuine experts tend to underestimate theirs. The incompetent lack the metacognitive ability to recognise their own incompetence — you have to know enough about a subject to know what you don't know. This is why the most confident voice in the room is often the least informed, why beginners give advice freely while experts hedge constantly, and why social media has produced an epidemic of certitude about complex topics.