32. Dunning–Kruger Effect

People can draw bad conclusions and made bad choices. And if it combines with low competence Dunning–Kruger emerge: people can't be aware of their own errors due to the lack of competence. As a result people tend to overestimate their own skills and knowledge when it is on the low level. Such a person also tends to incorrectly estimate the level of skill of another person.

Additional information:
J. Ehrlinger, K. Johnson, M. Banner, D. Dunning, J. Kruger, “Why the unskilled are unaware”, Organizational Behavior and Human Decision Processes 105 (2008).