Abstract
Paranoia (believing others intend harm) and excess teleological thinking (ascribing too much purpose) are non-consensual beliefs about agents. Human vision rapidly detects agents and their intentions. Might paranoia and teleology have roots in visual perception? Using displays that evoke the impression that one disc ('wolf') is chasing another ('sheep'), we find that paranoia and teleology involve perceiving chasing when there is none (studies 1 and 2) - errors we characterize as social hallucinations. When asked to identify the wolf or the sheep (studies 3, 4a, and 4b), we find high-paranoia participants struggled to identify sheep, while high-teleology participants were impaired at identifying wolves - both despite high-confidence. Both types of errors correlated with hallucinatory percepts in the real world. Although paranoia and teleology both involve excess perception of agency, the current results collectively suggest a perceptual distinction between the two, perhaps with clinical import.