Vaccination status in triage decisions: Identifying effects of punishment and in-group bias among the general public

It has been argued that vaccinated patients should be prioritized over unvaccinated patients in life and death triage decisions. To ensure public support, policies need to take views from the general public into account. Empirical evidence on the preferences of the general public is overall in line with prioritizing vaccinated patients. In this study, it is argued that effects of pro-social punishment and in-group bias can explain unequal treatment of vaccinated and unvaccinated patients in triage decisions made by lay persons. Moreover, it is argued that correctly identifying punishment effects requires control for in-group biases. Data from a conjoint experiment with English speaking adults from North America and Europe ( N = 1 , 987 ) were used to test this theoretical argument. Participants were asked to choose one of two patients to receive a life-saving respiratory ventilator. The patients differed randomly in terms of their vaccination status along with other medical and social characteristics. The results indicate that unequal treatment of vaccinated and unvaccinated patients can be attributed to in-group biases for unvaccinated participants, while vaccinated participants show evidence for in-group biases as well as punishment effects. These findings highlight the importance of a nuanced, theory-based understanding of public preferences in triage decisions.