In 1999, in the Journal of Personality and Social Psychology, my then graduate student Justin Kruger and I published a paper that documented how, in many areas of life, incompetent people do not recognize—scratch that, cannot recognize—just how incompetent they are, a phenomenon that has come to be known as the Dunning-Kruger effect. Logic itself almost demands this lack of self-insight: For poor performers to recognize their ineptitude would require them to possess the very expertise they lack. To know how skilled or unskilled you are at using the rules of grammar, for instance, you must have a good working knowledge of those rules, an impossibility among the incompetent. Poor performers—and we are all poor performers at some things—fail to see the flaws in their thinking or the answers they lack.
A whole battery of studies conducted by myself and others have confirmed that people who don’t know much about a given set of cognitive, technical, or social skills tend to grossly overestimate their prowess and performance, whether it’s grammar, emotional intelligence, logical reasoning, firearm care and safety, debating, or financial knowledge. College students who hand in exams that will earn them Ds and Fs tend to think their efforts will be worthy of far higher grades; low-performing chess players, bridge players, and medical students, and elderly people applying for a renewed driver’s license, similarly overestimate their competence by a long shot.