The prosocial phenotype and co-operative health protective behaviors: Insights from COVID-19

Objective: Identifying factors associated with co-operative health-protective behaviors (e.g., vaccination and social distancing) is critical during crises requiring collective action. This research examines two hypotheses in the context of the COVID-19 pandemic: (a) the situational-strength hypothesis, which predicts that the impact of prosocial preferences on repeated low-cost co-operative actions (e.g., adherence to government guidelines) is moderated by situational ambiguity (e.g., clarity of guidelines); and (b) the vaccination-altruism hypothesis, predicting prosocial individuals are more likely to undertake high-cost co-operative actions (e.g., initial COVID-19 vaccination) due to other-regarding motives. Method: Study 1 (N = 2, 861) assessed four prosocial behaviors (blood donation, organ donor registration, monetary donation, and volunteering) and three classic co-operative games (dictator, trust, and public goods) to validate a prosocial-phenotype (PP) measure. Study 2 (N = 3, 077) utilized an eight-wave U.K. panel survey (March 2020–July 2021) to test the situational strength and vaccination-altruism hypotheses. Results: Study 1 found that past prosocial behavior was significantly correlated with behavior in co-operative games, supporting construction of the PP measure. In Study 2, higher PP, in line with the situational-strength hypothesis, was associated with greater adherence to guidelines, but only when rules were ambiguous. Higher PP was also associated with greater stated willingness and uptake of vaccination. Although self-protection was the most common motive to vaccinate, high-PP individuals were more likely to cite protecting others and achieving herd immunity. Conclusion: Prosociality plays a dynamic role in influencing both low- and high-cost co-operative health protective behaviors, offering insights for public health strategies in future crises.