Communicating scientific uncertainty in the early stages of the COVID-19 pandemic: A message experiment.

The World Health Organization (WHO) officially declared COVID-19 a pandemic on March 11, 2020. It was a time of significant uncertainty as experts were not yet certain whether social distancing behaviors were necessary to slow the spread of the virus. Some public communicators opted to acknowledge uncertainty based on the limited evidence, whereas others downplayed uncertainty. This situation provided researchers with an opportunity to advance theory by explicating and testing cognitive responses to message uncertainty. Immediately following the WHO declaration (March 13-19, 2020), U.S. adults (N = 1186) were randomly assigned to one of six conditions in a 2 (message uncertainty: low, high) × 3 (argument support: expert, threat, precedent) between-participants experiment. Overall, perceived uncertainty negatively mediated the impact of message uncertainty on intentions. However, participant education was a key moderator. For those with more than a high school education, uncertain messages were related to higher intentions to social distance through increased critical reflection. For those with a high school education or less, uncertain messages were related to lower intentions through decreased message credibility.