Free will and scientific determinism beliefs and the support for physician-assisted death

Public attitudes surrounding support for or opposition to physician-assisted death (PAD) have largely been examined through broad factors such as religiosity. While religious beliefs undoubtedly play a role, we contend that existential lay beliefs, such as free will and scientific determinism, offer additional explanatory value. Across four studies (<i>N</i> = 1,548), utilizing both university and Prolific samples, we found mostly consistent evidence that free will beliefs were negatively associated with PAD support, whereas scientific determinism beliefs were positively associated. A mini-meta-analysis supported these patterns. Importantly, partial correlations across studies indicated that these associations held even after accounting religiosity. To explain these relationships, we proposed and found support for two psychological mechanisms: meaning-making expectations and perceived target mattering. Although limited to cross-sectional correlational data, these findings provide preliminary evidence that existential lay beliefs may shape attitudes toward PAD.