Kruger and Dunning noted a number of previous studies which tend to suggest that in skills as diverse as reading comprehension, operating a motor vehicle, and playing chess or tennis, “ignorance more frequently begets confidence than does knowledge” (as Charles Darwin put it). They hypothesized that with a typical skill which humans may possess in greater or lesser degree,
- Incompetent individuals tend to overestimate their own level of skill.
- Incompetent individuals fail to recognize genuine skill in others.
- Incompetent individuals fail to recognize the extremity of their inadequacy.
- If they can be trained to substantially improve their own skill level, these individuals can recognize and acknowledge their own previous lack of skill.
Dunning-Kruger effect – Wikipedia
This explains a lot.
Hat tip to Tim Walker for mentioning the effect.