Manipulating free will beliefs using online video games.

Research in social psychology and experimental philosophy has investigated lay people's free will beliefs (FWB). Using different approaches (i.e. experimental manipulations and vignette studies), they investigated how FWB relate to other concepts, and whether changing FWB has an impact on downstream processes such as social behavior. However, both approaches have shortcomings. While experimental manipulations used in social psychology suffer from demand effects, vignettes used in experimental philosophy are often highly abstract. Across two pre-registered studies, we developed a new approach by merging them in an online video game setting. Using this novel, experience-based FWB manipulation, we found that decreasing FWB impacted variables such as perceived control and responsibility in both studies. While the experience-based manipulation influenced participants' beliefs in free will within the context of the experience ("Within the context of the scenario, would the agent believe in free will?") in the first study, this manipulation effect did not transfer to participants' general FWB ("Do you believe in free will?") in the second study. Overall, our findings suggest a way forward in studying laypeople's beliefs in free will.