Overconfidence has been studied in 3 distinct ways. Overestimation is thinking that you are better than you are. Overplacement is the exaggerated belief that you are better than others. Overprecision is the excessive faith that you know the truth. These 3 forms of overconfidence manifest themselves under different conditions, have different causes, and have widely varying consequences. It is a mistake to treat them as if they were the same or to assume that they have the same psychological origins.
| INTRODUCTIONResearch on overconfidence employs a diversity of approaches and measures as if they all tap the same underlying psychological construct. This is an error. Overconfidence is not a single unitary construct. In this paper, we note the inconsistent results between different approaches to the study of overconfidence. These inconsistencies are further muddled by multiple usages of the term "overconfidence" in the vernacular. In the interests of clarity, we begin this review with a few definitions, beginning with the definition of overconfidence: greater confidence than reality justifies. Measuring overconfidence necessitates a comparison between beliefs and reality. We then consider each of the three types of overconfidence in turn: overestimation, overplacement, and overprecision. Given that overconfident beliefs are (by definition) incorrect, we then confront the question:Can overconfidence be useful? Finally, we consider one way in which researchers assume there is psychological coherence to overconfidence: stable individual differences. Here again, we will question the solidity of the phenomenon and argue that overconfidence does not appear to be a stable difference between people. Our review highlights the diversity and inconsistency in manifestations of overconfidence.There is a great deal of work on confidence, self-efficacy, self-esteem, optimism, and self-enhancement that includes no measure of overconfidence because there is no accuracy benchmark against which beliefs can be compared. The research that does compare beliefs with reality to assess overconfidence has usually employed one of three measures: overestimation, overplacement, or overprecision. Overestimation is thinking that you are better than you are. Donald Trump's claim to be worth $10 billion (White, 2016) represented an overestimate relative to a more credible estimate of $4.5 billion by Forbes magazine (Peterson-Withorn, 2016). A second measure of overconfidence is overplacement: the exaggerated belief that you are better than others. When Trump claimed to have achieved the largest electoral victory since Ronald Reagan (Cummings, 2017), he was overplacing himself relative to other presidents. A third form of overconfidence is overprecision: being too sure you know the truth. Trump displays overprecision when he claims certainty about views, which are contradicted by reality. . Does the better-than-average effect show that people are overconfident?: Two experiments.