Understanding visual barriers: evidence for Level 1 perspective taking in an orang-utan, Pongo pygmaeus

An adult female orang-utan used an untutored series of physical manipulations to guide humans to food placed beyond her reach. Through a series of experiments that involved different visual occlusions, this orang-utan appeared to take into account humans’ visual states when using them to retrieve inaccessible goals. These data suggest that she was able to […]