Overconfidence Bias

PMC - Overconfidence over the lifespan | Wikipedia - Overconfidence Effect | Scribbr - Overconfidence Bias

Overconfidence Bias is a cognitive bias where people systematically have more confidence in the accuracy of their knowledge and judgments than is objectively justified. Research originated in psychological studies during the 1970s-1980s, with significant contributions from researchers like Baruch Fischhoff and Paul Slovic. The bias manifests in three distinct forms: overestimation (overrating actual performance), overplacement (overrating performance relative to others), and overprecision (excessive certainty in the accuracy of beliefs). Classic studies using 90% confidence intervals consistently show that people’s actual accuracy rates fall around 50%, demonstrating a dramatic miscalibration between perceived and actual competence. Social psychologist Scott Plous called it the most prevalent and potentially catastrophic problem in judgment and decision-making.