1.17—Perceived risk and actual risk

People often judge risk using vividness, familiarity and perceived control rather than the measured probability alone. Rare dramatic events can feel more likely than common gradual hazards.

Actual risk is estimated from population data and an agreed time frame; perceived risk is an individual judgement that can be shifted by media coverage, personal experience and trust in the source.

A person may fear a rare treatment side effect after seeing a news story but underestimate the cumulative CVD risk of smoking because it is familiar. The decision changes when absolute risk and comparison groups are made explicit.

Good communication does not simply replace perception with a number: it explains denominator, time horizon, uncertainty and the action that can change risk.

A perception is not “wrong” merely because it differs from an average statistic; context and values matter. But a decision should not confuse emotional salience with measured probability.