Dunning–Kruger effect
The Dunning–Kruger effect is a cognitive bias whereby people with low ability, expertise, or experience regarding a certain type of task or area of knowledge tend to overestimate their ability or knowledge.

The concept of the Dunning-Kruger effect is based on a 1999 paper by Cornell University psychologists David Dunning and Justin Kruger. The pair tested participants on their logic, grammar, and sense of humor, and found that those who performed in the bottom quartile rated their skills far above average. For example, those in the 12th percentile self-rated their expertise to be, on average, in the 62nd percentile.

The researchers attributed the trend to a problem of metacognition—the ability to analyze one’s own thoughts or performance. “Those with limited knowledge in a domain suffer a dual burden: Not only do they reach mistaken conclusions and make regrettable errors, but their incompetence robs them of the ability to realize it,” they wrote.

What causes the Dunning-Kruger effect?

Confidence is so highly prized that many people would rather pretend to be smart or skilled than risk looking inadequate and losing face. Even smart people can be affected by the Dunning-Kruger effect because having intelligence isn’t the same thing as learning and developing a specific skill. Many individuals mistakenly believe that their experience and skills in one particular area are transferable to another.

src: Bob Moran

src: psychologytoday.com