Forty years of research on Unrealistic Optimism - a delusion that negative events are less likely and positive events are more likely to happen to oneself (in comparison to others) - has proved to be robust. Importantly, as a result, people holding this bias reduce their engagement in health prevention and following medical recommendations, etc., leading to the conclusion that this bias is dangerous. However, there is hardly any research on how to reduce this bias. To address this issue, an experiment in the real-life context of the COVID-19 pandemic was run. It was found that participants’ Unrealistic Optimism was reduced when they were exposed to the behavior of others who did not follow medical recommendations.