During the COVID-19 pandemic, public health guidance (e.g., regarding the use ofnon-medical masks) changed over time. Although many revisions were a result ofgains in scientific understanding, we nonetheless hypothesized that makingchanges in guidance salient would negatively affect evaluations of experts andhealth-protective intentions. In Study 1 (N = 300), wedemonstrate that describing COVID-19 guidance in terms of inconsistency (versusconsistency) leads people to perceive scientists and public health authoritiesless favorably (e.g., as less expert). For participants in Canada(n = 190), though not the U.S. (n = 110),making guidance change salient also reduced intentions to download a contacttracing app. In Study 2 (N = 1399), we show that a briefforewarning intervention mitigates detrimental effects of changes in guidance.In the absence of forewarning, emphasizing inconsistency harmed judgments ofpublic health authorities and reduced health-protective intentions, butforewarning eliminated this effect.
