Exaggerated Expectation
A more extreme version of confirmation bias (interpreting information in such a way that it confirms a preconception), where the reality, when compared to real-world evidence, turns out to be less severe or extreme than the expectations.
Origin
Exaggerated expectation emerged from research on expectancy bias and confirmation bias, which Francis Bacon described in the 17th century and Peter Wason formalized in 1960. The phenomenon relates to belief perseverance—retaining expectations despite contradictory evidence. Exaggerated expectation specifically describes predicting more extreme outcomes than actually occur, linking observer-expectancy effects to cognitive bias in psychology. The bias appears in research, forecasting, and everyday judgments where expectations systematically overshoot reality.