Perceived Corona virus exposure as a function of interpersonal distance and time of a conversation

Airborne SARS-CoV2 virus exposure, interpersonal distance, face mask and perceived risk of infection

Participants judged the risk of an infection during a face to face conversation at different interpersonal distances from a SARS-CoV-2 infected person who wore a face mask or not, and in the same questionnaire answered questions about Corona related issues. Keeping a distance to an infected person serves as a protective measure against an infection. When an infected person moves closer, risk of infection increases. Participants were aware of this fact, but underestimated the rate at which the risk of infection increases when getting closer to an infected person, e.g., from 1.5 to 0.5 m (perceived risk increase = 3.33 times higher, objective = 9.00 times higher). This is alarming because it means that people can take risks of infection that they are not aware of or want to take, when they approach another possibly virus infected person. Correspondingly, when an infected person moves away the speed of risk decrease was underestimated, meaning that people are not aware of how much safer they will be if they move away from an infected person. The perceived risk reducing effects of a face mask were approximately correct. Judgments of infection risk at different interpersonal distances (with or without a mask) were unrelated to how often a person used a mask, avoided others or canceled meetings during the COVID-19 pandemic. Greater worry in general and in particular over COVID-19, correlated positively with more protective behavior during the pandemic, but not with judgments of infection risk at different interpersonal distances. Participants with higher scores on a cognitive numeracy test judged mask efficiency more correctly, and women were more worried and risk avoiding than men. The results have implications for understanding behavior in a pandemic, and are relevant for risk communications about the steep increase in risk when approaching a person who may be infected with an airborne virus.

Estimating perceptions of the relative COVID risk of different social-distancing behaviors from respondents' pairwise assessments

How do people compare the effectiveness of different social-distancing behaviors in avoiding the spread of viral infection? During the COVID pandemic, we showed 676 online respondents in the United States, United Kingdom, and Israel 30 pairs of brief videos of acquaintances meeting. We asked respondents to indicate which video from each pair depicted greater risk of COVID infection. Their choices imply that on average, respondents considered talking 14 min longer to be as risky as standing 1 foot closer, being indoors as standing 3 feet closer, being exposed to coughs or sneezes as 3 to 4 ft closer, greeting with a hug as 7 ft closer, and with a handshake as 5 ft closer. Respondents considered properly masking as protecting the wearer and interlocutor equally, removing the mask entirely or only when talking as standing 4 to 5 ft closer but wearing it under the nose as only 1 to 2 ft closer. We provide weaker evidence on beliefs about the interaction effects of different behaviors. In a more limited, ex post analysis, we find little evidence of differences in beliefs across subpopulations.