Experimental verification of the causal effect of religiosity and spirituality on medical decisions: Three experimental studies

The COVID-19 pandemic has increased awareness of health-related decisions, prompting research into vaccine refusal and alternative treatments. Recent studies have identified religiosity and spirituality as potential factors, challenging their traditionally positive health associations. We examined the causal impact of religiosity and spirituality on health beliefs across three experimental studies (total N = 483). Participants were recruited through convenience sampling, with multinational samples in Studies 1 and 2 and a Polish sample in Study 3. Although both religiosity and spirituality were positively associated with vaccine skepticism and CAM usage intentions, only spirituality showed a causal effect by increasing CAM usage intentions. Our results emphasize the need for causal, within-person analyses rather than relying solely on cross-sectional correlational studies.