Imitation, Grammatical Development, and the Invention of Protogrammar by an Ape
The conservative nature of evolution, plus wide agreement that human language has a strong innate basis (Chomsky, 1965, 1967; Goldin-Meadow, 1978; Goldin-Meadow & Mylander, 1984; Lenneberg, 1967; Lieberman, 1984), suggests that much of the genetic basis of human language must be shared not only with present-day chimpanzees but also with our common primate ancestor. There is evidence that a species of chimpanzee, Pan paniscus, shows more resemblance than humans or the other great apes to this common ancestor (Zihlman, Cronin, Cramer, & Sarich, -1978). Pan Paniscus is also closer to humans in sociosexual behavior (SavageRumbaugh, 1984) and prolonged maturation (Kuroda, 1989) than the other, more commonly studied chimpanzee species, Pan troglodytes. For these reasons, our selected species, Pan paniscus (also known as the pygmy chimpanzee or bonobo) is a particularly promising model for the behavioral exploration of human evolution.