Recent personal and vicarious experience with COVID-19 affects personal, but not comparative optimism: a large longitudinal study.

We examined whether personal and vicarious experience with COVID-19 entails change in personal and comparative optimism (the belief that one is less at risk for hazards than others, also known as unrealistic optimism, optimistic bias, or illusion of unique invulnerability) in a large (N ≈ 5000) 5-Wave longitudinal study conducted in Belgium in December 2020-May 2021. Participants reported their experience with COVID-19 as well as their expectations concerning the likelihood that they and the average peer would get infected and, after an infection, would suffer severe disease or rather register a good outcome. Neither personal nor vicarious experience entailed change in comparative optimism, but both entailed reduced personal optimism about the likelihood of an infection and enhanced personal optimism concerning a good outcome. Personal and vicarious experience entailed reduced perceived control over the likelihood of infection and the likelihood of severe disease, and vicarious experience also reduced perceived control over a good outcome. However, changes in optimism were not mediated by effects on perceived control. We discuss methodological implications for research on determinants of risk perception as well as the implications of our findings for public health communication appealing to people's personal and vicarious experiences.