OBJECTIVES: To investigate whether citizens' adherence to health-protective non-pharmaceutical interventions (NPIs) during the COVID-19 pandemic is predicted by identity leadership, wherein leaders are perceived to create a sense of shared national identity. DESIGN: Observational two-wave study. Hypotheses testing was conducted with structural equation modelling. SETTING: Data collection during the COVID-19 pandemic in China, Germany, Israel and the USA in April/May 2020 and four weeks later. PARTICIPANTS: Adults in China (n=548, 66.6% women), Germany (n=182, 78% women), Israel (n=198, 51.0% women) and the USA (n=108, 58.3% women). MEASURES: Identity leadership (assessed by the four-item Identity Leadership Inventory Short-Form) at Time 1, perceived shared national identification (PSNI; assessed with four items) and adherence to health-protective NPIs (assessed with 10 items that describe different health-protective interventions; for example, wearing face masks) at Time 2. RESULTS: Identity leadership was positively associated with PSNI (95% CI 0.11 to 0.30, p<0.001) in all countries. This, in turn, was related to more adherence to health-protective NPIs in all countries (95% CI 0.03 to 0.36, 0.001≤p≤0.017) except Israel (95% CI -0.03 to 0.27, p=0.119). In Germany, the more people saw Chancellor Merkel as engaging in identity leadership, the more they adhered to health-protective NPIs (95% CI 0.04 to 0.18, p=0.002). In the USA, in contrast, the more people perceived President Trump as engaging in identity leadership, the less they adhered to health-protective NPIs (95% CI -0.17 to -0.04, p=0.002). CONCLUSIONS: National leaders can make a difference by promoting a sense of shared identity among their citizens because people are more inclined to follow health-protective NPIs to the extent that they feel part of a united 'us'. However, the content of identity leadership (perceptions of what it means to be a nation's citizen) is essential, because this can also encourage people to disregard such recommendations.
