The affect heuristic can evoke a format effect so that different ways of expressing the level of likelihood of an event happening can cause different perceptions of the level of risk. We conducted 3 studies to test the hypothesis that a format effect is not always present at every level
of probability, and even when a format effect occurs, it depends on risk level and emotion. In Study 1, the risk of a flood threatening participants' homes (familiar risk) regardless of change in emotion, occurred only at a 5% probability level. In Study 2, when facing an unfamiliar risk (being
infected by Chikungunya fever), regardless of change in emotion, a format effect occurred at the level of 5% probability only when emotion was positive. In Study 3, a format effect occurred at a 5% probability level when prior emotion expectation was positive and risk consequences were emphasized.
We can conclude that the format effect depends on changes in risk level and emotions.
The inhibitory effect of numeracy on affect heuristic in food risk perception
