Tentative support for the hypothesis that belief in free will increases support for economic inequality; but attempts to experimentally manipulate belief in free will are often underpowered to detect an overall change in a dependent variable

Mercier, Brett G., Dylan Wiwad, Paul Piff, Lara aknin, Angela R. Robinson, and Azim Shariff. 2018. “Does Belief in Free Will Increase Support for Economic Inequality?.” PsyArXiv. November 2. doi:10.31234/osf.io/k45ud

Abstract: In five studies, we test whether belief in free will influences support for economic inequality. Study 1 shows that on a country-level, belief in free will is correlated with support for economic inequality. Study 2 demonstrates that individuals with stronger belief in free will are more likely to support inequality. In Studies 3 and 4, we manipulate belief in free will and find mixed results. We do not find evidence that the manipulation produces an overall change in support for inequality. However, we do find evidence that the data are consistent with a mediation model where the manipulation has an indirect effect on support for inequality through a change in belief in free will. Study 5 finds that people report that they would be more willing to support inequality in a hypothetical universe where free will exists compared to one where it does not. Our results provide tentative support for the hypothesis that belief in free will increases support for economic inequality. Additionally, our research illustrates how attempts to experimentally manipulate mediating variables, such as belief in free will, are often underpowered to detect an overall change in a dependent variable.