title: Chimpanzees know that others make inferences.
abstract: If chimpanzees are faced with two opaque boards on a table, in the context of searching for a single piece of food, they do not choose the board lying flat (because if food was under there it would not be lying flat) but, rather, they choose the slanted one- presumably inferring that some unperceived food underneath is causing the slant. Here we demonstrate that chimpanzees know that other chimpanzees in the same situation will make a similar inference. In a back-and-forth foraging game, when their competitor had chosen before them, chimpanzees tended to avoid the slanted board on the assumption that the competitor had already chosen it. Chimpanzees can determine the inferences that a conspecific is likely to make and then adjust their competitive strategies accordingly.
authors.affiliation: Department of Developmental and Comparative Psychology, Max Planck Institute for Evolutionary Anthropology, D-04103 Leipzig, Germany. martin_schmelz@eva.mpg.de
authors.forename: Martin
authors.initials: M
authors.lastname: Schmelz
authors.forename: Josep
authors.initials: J
authors.lastname: Call
authors.forename: Michael
authors.initials: M
authors.lastname: Tomasello
mesh_terms: D000818:Animals; D001364:Awareness; D002755:Choice Behavior / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003163:Competitive Behavior; D005260:Female; D008297:Male; D002679:Pan troglodytes / Q000523:psychology*; D012938:Social Perception; D056345:Theory of Mind / Q000502:physiology*