Glossary
Normalcy Bias
What is normalcy bias?
Normalcy bias is a label for underestimating a warning or disruptive event because conditions are expected to remain normal. Its status as a general psychological explanation is disputed. A failure to prepare or evacuate does not, by itself, show the bias.
An example of normalcy bias
Imagine someone dismissing a hurricane warning because earlier storms caused little damage. That is what the label is meant to describe: the expectation of normality outweighs the current warning.
But the example is not a diagnosis of every person who stays. Access to warnings, trust, transportation, money, caring duties, and other practical barriers can all shape protective action. Those conditions must be examined before behavior during a disaster or pandemic is attributed to a bias.
Normalcy bias and optimism bias
The two labels can overlap, but they emphasize different judgments. Normalcy bias concerns an expectation that conditions will continue much as they have. Optimism bias concerns overestimating favorable outcomes or underestimating unfavorable ones. Neither label, by itself, identifies the cause of a particular decision.
A broader account of protective action
Research on protective action considers warning comprehension, threat perceptions, available responses, and practical barriers together. That broader view matters because a warning can be believed yet remain hard to act on.
Yamori’s critical review also warns that calling a decision “normalcy bias” after a disaster can impose a tidy retrospective explanation on an uncertain situation. The label should not replace an investigation of what the person knew, believed, and could do at the time.