Previous research suggests that belief in free will correlates positively with intention perception. However, whether belief in free will is also related to more basic social processes is unknown. Based on evidence that biological motion is an intention-carrier, we investigate if belief in free will and related two beliefs, namely belief in dualism and belief in determinism, are associated with biological motion perception. Signal Detection Theory (SDT) was used to measure participants’ ability to detect biological motion from scrambled background noise (d') and their response bias (c) in doing so. In two experiments, we found that belief in determinism and belief in dualism, but not belief in free will, were associated with the perception of biological motion. However, no causal relationship was found when experimentally manipulating free will-related beliefs. In general, our research suggests that basic social processes, like biological motion perception, can be predicted by high-level beliefs.