Orang-utans rely on orientation cues and egocentric rules when judging others' perspectives in a competitive food task

► We investigated the orang-utans' visual perspective taking in a competitive food task. ► The competitor could only see the stealing of one out of two pieces of food. ► The orang-utans succeeded when he was oriented towards one but not the other piece. ► They failed to discriminate between an opaque and a clear barrier blocking his vision.