Shared social identity and social norms shape risk-taking at mass gatherings

Shared social identity and social norms are often un(der)recognized within mass gatherings health literature, yet they can increase infectious disease transmission by motivating people to engage in risk-taking behaviours. Across three experiments (Ntotal = 1551), we investigated how shared social identities, perceived norms of resource-sharing, and perceived riskiness of sharing interact to shape decisions that can lead to disease transmission. In Experiment 1 (N = 528), we examined how shared social identity and perceived descriptive norms affect the likelihood of crowd members sharing resources that may contribute to disease spread. We then replicated this in Experiment 2 (N = 511) using perceived injunctive norms. In Experiment 3 (N = 512), we explored how high shared social identity, perceived norms, and perceived health risks of resource-sharing impact the likelihood of sharing that may, in turn, increase infectious disease transmission at mass gatherings. We found that high shared social identity interacts with perceived descriptive and injunctive norms, and low health risk perceptions, to increase the likelihood of accepting resources and giving resources at mass gatherings. We discuss the theoretical and practical implications for researchers, practitioners, and policymakers to build effective strategies to mitigate infectious disease transmission at mass gatherings.