A common social comparison bias -the better-than-average-effect- is frequently described as psychologically equivalent to the individual judgment bias known as overconfidence. However, research has found hard-easy effects for each bias that yield a seemingly paradoxical reversal: Hard tasks tend...

Using the wisdom of crowds -- combining many individual judgments to obtain an aggregate estimate -- can be an effective technique for improving judgment accuracy. In practice, however, accuracy is limited by the presence of correlated judgment errors, which often emerge because information is...