Belief in free will has meaningful consequences on morally relevant behaviors; however, there is limited research identifying a potential mechanism for these effects. Two studies explored whether subjective perceptions of knowing one's "true self" play a mediating role in this relationship. Prosociality served as the primary outcome variable in these studies. Study 1 tested the hypothesis that attenuating free will beliefs reduces people's true self-knowledge such that they experience and engage in less prosocial emotions, intentions, and behavior. Participants completed a free will manipulation, measure of true self-knowledge, and their prosocial emotions, intentions, and behavior towards different people in need. Study 2 was a short-term motivational intervention aimed to augment belief in free will and assessed whether strengthening people's belief in free will increases feelings of true self-knowledge such that people engage in more virtuous behaviors. Participants in the free will intervention condition were asked to write about experiences where they utilized their free will in vivid detail for three days. Belief in free will, true self-knowledge, and prosocial measures were assessed on day four. Both studies did not find direct evidence for true self-knowledge as a mediator for these effects. The current research highlights the ongoing need to identify potential mechanisms for the effect of belief in free will on moral outcomes. Limitations and directions for future research are discussed.
