The Peter Principle is a proposition that states that the members of an organization where promotion is based on achievement, success, and merit, will eventually be promoted beyond their level of ability. The principle is commonly phrased, "Employees tend to rise to their level of incompetence." In more formal parlance, the effect could be stated as: employees tend to be given more authority until they cannot continue to work competently. It was formulated by Laurence J. Peter and Raymond Hull in their 1969 book The Peter Principle, a humorous treatise, which also introduced the "salutary ...

The Dunning–Kruger effect is a cognitive bias in which unskilled individuals suffer from illusory superiority, mistakenly rating their ability much higher than average. This bias is attributed to a metacognitive inability of the unskilled to recognize their mistakes. Actual competence may weaken self-confidence, as competent individuals may falsely assume that others have an equivalent understanding. David Dunning and Justin Kruger of Cornell University conclude, "the miscalibration of the incompetent stems from an error about the self, whereas the miscalibration of the highly compete...