In two studies conducted in Hong Kong during and immediately after the outbreak of severe acute respiratory syndrome (SARS), participants displayed several social cognitive biases when they estimated the prevalence of and inferred the motives underlying SARS preventive behaviors. First, participants who practiced preventive behaviors (practicers) consistently estimated that more people practiced such behaviors than did non-practicers (false consensus bias). Second, for some preventive behaviors, participants believed that their own behaviors were more motivated by prosocial concerns (relative to self-interest) than were other practicers (pluralistic ignorance). Finally, non-practicers underestimated the importance of prosocial concerns underlying some preventive behaviors (actor-observer bias). We discussed the relevance of these social cognitive biases to health education and to Hong Kong people's psychological reactions to SARS.
Keywords: actor‐observer bias; false consensus; pluralistic ignorance; severe acute respiratory syndrome (SARS); social cognitive biases.