Dunning‑Kruger Effect Shows How Internet Users Overestimate Their Expertise

Psychologists David Dunning and Justin Kruger identified a cognitive bias in 1999 that causes people with limited knowledge to overestimate their abilities while experts tend to underestimate theirs. Experiments showed that low‑performing students rated themselves above average on tasks such as logic, grammar and humor, whereas high‑performing students gave modest self‑assessments. Online platforms amplify this effect: easy access to information, anonymity and algorithmic echo chambers enable individuals to form and loudly express opinions after only brief exposure to a topic, often confronting seasoned professionals with unfounded confidence. The phenomenon is explained by three pillars: ignorance of complexity, overestimation of one’s capability, and underappreciation of true expertise. Recognising the Dunning‑Kruger effect helps explain why laypeople sometimes dominate discussions on social media, politics, health and finance despite lacking substantive knowledge.