The relationship between belief in free will and intention attribution depends on the decision stage

Humans have a general tendency to attribute intentionality to other people. Recently it has been demonstrated that such intention attribution depends on whether it happens spontaneously or with deliberation. More specifically, there is a bias to overestimate intentionality only for intention attribution under time pressure when deliberate processes are limited. In addition, more recently, research has suggested that how much intentionality individuals attribute to other people’s behavior also depends on their belief in free will. The first aim of the current study was to replicate the relationship between intention attribution and free will beliefs with an established paradigm based on ratings of text passages. More importantly we wanted to investigate whether belief in free will is more strongly related to spontaneous or deliberate intention attribution. Across two experiments, participants were asked to judge if the protagonist in a sentence was acting on purpose or by accident. The results revealed a positive correlation between belief in free will and intention attribution when participants had to respond under time pressure (Experiment 2) but not when there was no time constraint (Experiment 1). These results suggest that free will beliefs are related to spontaneous intention attribution but not to more deliberate attribution of intentions.