ABSTRACT
Various techniques can provide data for cross-species comparisons of cognitive abilities. Researchers use protocols that range from operant laboratory procedures (see Kamil, 1988; Roitblat, Bever, & Terrace, 1984) to field studies that examine how animals respond to different types of auditory playbacks (e.g., Cheney & Seyfarth, 1985, Seyfarth & Cheney, this volume, chapter 10). The technique that my students and I use, which involves interspecies communication, is still considered somewhat unconventional (e.g., Seidenberg & Petitto, 1987) although it has been in existence for over two decades. Our studies on an African Grey parrot (Psittacus erithacus), like the pioneering projects on chimpanzees (Pan troglodytes, Gardner & Gardner, 1978; Premack, 1976, Rumbaugh, 1977) and dolphins (Tursiops truncatus, Herman, 1980), use a two-step procedure in which the parrot is first taught a communication code based on certain aspects of human language. The resultant capacity for animal-human communication then provides a channel for assessing the bird’s cognitive abilities (see Pepperberg, 1981, 1986, 1990c, 1991).
