Seeing the glass as half full is usually a good thing. Optimism in life has been linked to psychological and physical health, career success, and romantic fulfillment—even when our perception of risks and rewards entails a considerable departure from reality. In fact, lack of optimism can signal mental illness: some studies have shown that depressed people judge their circumstances more realistically than people who are not depressed—a phenomenon called “depressive realism.”

The other side of the coin, unrealistic optimism, is one example of so called “positive illusions” that enhance our well-being through a bit of (usually) harmless self-deception. The problem arises when our rosy miscalculations get in the way of our safety. A person suffering from a life-threatening disease may not seek medical treatment if they feel unreasonably optimistic about their chances of survival without therapeutic intervention. Similarly, people underestimating their risk of infection may not properly protect themselves in the face of potential exposure to a grave illness.

Is unrealistic optimism prevalent during the current coronavirus pandemic? A group of scientists from the University of Opole and the SWPS University of Social Sciences and Humanities in Poland set out to answer this question in a sample of university students. Their results, published earlier this month in the Journal of Clinical Medicine, reveal a widespread incidence of unrealistic optimism among the study participants regarding their chances of contracting Covid-19.

Dariusz Dolinski, Barbara Dolinska, Barbara Zmaczynska-Witek, Maciej Banach, and Wojciech Kulesza conducted their study in three data-collection phases, centered around the announcement of the first wave of coronavirus infections in Poland. The researchers analyzed data from 171 undergraduates (115 women and 56 men), all of which took part in the three phases. Each participant responded to a survey that asked, “How likely is it that you will become infected with coronavirus?” and “How likely is it that the average student of your sex in your class will become infected with coronavirus?” The first phase of the study took place on March 2nd and 3rd, 2020. Before then, there had been no confirmed coronavirus patients in Poland, but many cases had been reported in Germany (which borders Poland). On March 3rd, Poland’s Minister of Health officially announced that around 100 patients were hospitalized in Polish hospitals with suspected coronavirus, and that an additional 300 people were being quarantined. At the time of the announcement, the research team had already completed their data collection for the initial phase of the study. The morning after, on March 4th, the Minister of Health announced the first case (patient “0”) of coronavirus in Poland, at a special press conference. Upon this announcement, many Polish people rushed to acquire reserves of food, hygiene, and disinfecting products. Based on this information, Dolinski and colleagues decided to immediately carry out the second data-collection phase, on March 5th and 6th. Over the following two days, on March 6th and 7th, several new cases were reported in Poland, coinciding with reports of increased deaths and morbidity around Europe, and the announcement of coronavirus infections in 104 countries worldwide. The scientists thus carried out the third and final phase of the study on March 9th and 10th. On March 11th, the University of Opole closed, putting an end to the study.

The results revealed a general occurrence of unrealistic optimism among the study participants, as well as a statistically significant gender difference. Whereas unrealistic optimism was observed in men in the three data collection phases, in women it was restricted to the last two phases. Overall, study participants of either gender believed themselves to be at a lesser risk of infection than “the average student.” The findings could have important implications for regulations concerning social distancing, staying at home, and wearing masks outside. Unrealistically optimistic people, the researchers speculated, may be less compliant with public safety recommendations, contributing to the spread of coronavirus.

“We were astonished by the fact that unrealistic optimism prevailed in the light of the Covid-19 pandemic,” Dolinski and Kulesza said. “Our preliminary research [also shows that] unrealistic optimism may make us more vulnerable to Covid-19,” the researchers added. “In contrast, after the Chernobyl nuclear plant disaster, [we found that] people with unrealistic pessimism were more eager and proactive to stay safe from the nuclear cloud.”    

The scientists hope that people experiencing excessive optimism in the face of coronavirus exposure strive for higher realism. “You are just like any other person of your same age, gender, health, etc. You are not bulletproof.”