ABSTRACT
In this chapter, the author explains how to assess the mental states that accompany similar behaviors in different species. It examines several cases from author research program in which chimpanzees and human children exhibit strikingly similar behavior, and asks whether such behavioral similarity justifies an inference of comparable psychological similarity. Chimpanzees are remarkably social creatures. Menzel described the micro-genesis of such behaviors many years ago during a landmark set of studies of young chimpanzees, and in the ensuing decades many primatologists have urged us to consider such episodes as evidence that chimpanzees see one another as more than just hairy collections of limbs, torsos, and facial expressions moving through space. Finally, chimpanzees may also possess at least a tacit understanding of how another’s gaze is interrupted by solid, opaque surfaces. In general, the findings reveal that chimpanzees follow gaze with a sophistication comparable to that exhibited by 18-month-old human infants.
