Physical discomfort predicts parochial altruism during Pope Francis’s funeral

• Costly participation in Pope Francis’s funerary rites predicted increased charitable giving. • Physical discomfort selectively enhanced donations to a Catholic (ingroup) charity, but not to a neutral charity (Red Cross). • The effect was strongest among local participants, suggesting identity-contingent parochial altruism. • The results support self-signaling theories of ritual behavior. Large-scale public rituals often impose significant physical and psychological burdens, yet are widespread across cultures. Evolutionary theories often interpret such rituals through the lens of signaling, viewing them as credible displays of commitment to groups, norms, or beliefs. While much of this literature emphasizes interpersonal signaling, recent theoretical work highlights the potential for self-signaling, where individuals infer their own values by observing their own costly behavior. However, this mechanism remains underexplored. To test it, we conducted a field study during the funeral rites of Pope Francis, where hundreds of thousands queued for hours under challenging conditions to view his body lying in state. We found that higher self-reported discomfort predicted donations to a Catholic charity but not to a religiously neutral one. This effect was strongest among local participants and with stronger identification as Catholic. Our findings highlight an underemphasized dimension to signaling theory, offering new insights into the psychological pathways through which ritual participation shapes moral behavior.