Moral obligation, autonomous motivation, and COVID-19 vaccine hesitancy: Highlighting moral obligation increases reactance in hesitant individuals

Objectives: Understanding the predictors of Covid-19 vaccination intentions helps to inform communication strategies that encourage hesitant individuals to choose vaccination. This pre-registered research aimed to examine moral obligation and autonomous motivation as predictors ofCovid-19 vaccination intentions and reactance. The effects of messages highlighting moral obligation and using autonomy-supportive language, on reactance and vaccination intentions were subsequently explored. Design: A cross-sectional online survey measured morally relevant cognitions and autonomous motivation as predictors of Covid-19 vaccination intentions (Study 1). A randomised experimental online survey tested the effectiveness of messages which highlighted moral-obligation vs. personal protection and used autonomy-supportive vs. controlling messages, on intentions to vaccinate and reactance (Study 2). Methods: In Study 1 (N = 1029) participants who had not received a Covid-19 vaccine completed an online questionnaire including measures of autonomous motivation, moral obligation, reactance, intentions to vaccinate, and vaccine hesitancy. In Study 2 (N = 428) unvaccinated participants were assigned to one of four message conditions or to an information-only control group, and reported their reactance, intentions to vaccinate, and vaccine hesitancy Results: In Study 1, the results showed that morally relevant cognitions and autonomous motivation were associated with stronger vaccination intentions and lower reactance. In Study 2, messages highlighting moral obligation and those using less autonomy-supportive language elicited greater reactance. Conclusions: Although moral obligation and moral norms are a strong predictor of vaccination intentions, highlighting moral obligation in targeted messaging may elicit reactance effects. The research has implications for the design of communication encouraging vaccination in hesitant individuals.