Cognitive constraints of chimpanzees' theory of mind

Abstract

Like much other cognition, social cognition of great apes, or more specifically, chimpanzees (*Pan troglodytes*) embodies markers of both rich cognitive character and (somewhat) systematic limitations. This is opportune for a psychological theory that aims to outline the character of the chimpanzee's mind both in its opportunities and characteristic limitations. The theoretical space of theory of mind -- the ability to represent other animals' minds -- has been populated with accounts that delimit nonhuman and precocious human abilities from older humans. I deploy this heuristic in empirical (Chapters 2-4) and theoretical (Chapter 5) investigations of systematic representational limitations in chimpanzees' representational abilities. More specifically, in Chapter 2, I investigated their abilities to represent misleading appearances of objects and failed to fully replicate their reported success in tracking apparent size transformations of food items. In Chapter 3, I developed a communicative interaction task that leveraged chimpanzees' reactions to different violations of their food requests. Across two experiments, the chimpanzees failed to show a sensitivity to violations of communicative intentions that cannot be explained in instrumental reference. In Chapter 4, I adapted a different communicative task that leveraged pragmatic factors to tease out chimpanzees' tendencies to disambiguate their manual pointing gestural acts. I failed to find evidence of active disambiguation for the recipient's benefit. Finally, in Chapter 5, I developed a comprehensive and tractable system of cognitive constraints that might explain performance limitations of nonhuman primates found in the literature, as well as in the present project.