Grammatical combination in Pan paniscus: Processes of learning and invention in the evolution and development of language

On the Inseparability of Grammar and the Lexicon: Evidence from Acquisition, Aphasia and Real-time Processing

“…Before we turn to the question of grammar vs. the lexicon in adults with language disorders, we indulge in a brief digression regarding the putative dissociation between grammar and vocabulary reported in reviews of the literature on chimpanzees exposed to languagelike symbolic systems (Gardner, Gardner, & van Cantfort, 1989;Greenfield, 1991;Greenfield & Savage-Rumbaugh, 1990Savage-Rumbaugh, 1986;SavageRumbaugh, Brakke, & Wilkinson, 1989;Savage-Rumbaugh et al, 1993;Seidenberg & Petitto, 1979;Tomasello, 1992Tomasello, , 1994Tomasello & Call, in press;Tomasello & Camaioni, in press). It is often argued that these animals are quite capable of lexical acquisition, picking up expressive vocabularies of up to 200 symbols or signs.…”

Information, information transfer, and information processing

“…Ape language studies have consistently shown that chimpanzees can learn real symbolic relationships, although only under specific experimental conditions. Moreover, it has been shown that apes can also invent new symbolic rules themselves (Greenfield & Savage-Rumbaugh 1990). These data, and other literature on symbolization, were used by Deacon to propose that the gap between spontaneous animal communication systems and human languages is explained by significant differences between the cognitive abilities and neural structures of such species.…”

“…By contrast, in his fourth year sample, Kanzi averaged 10.2 utterances per hour. In a late sample from Kanzi's sixth year, Greenfield and Savage- Rumbaugh (1990) reported that on average 10.7% of Kanzi's utterances included two or more lexigrams. They also report that the experimenters themselves failed to achieve fluency with lexigrams.…”

Expertise and the evolution of consciousness

“…If an animal depends entirely upon environmental triggers to remember when and what to rehearse, skill development becomes extremely difficult, since the animal cannot self-trigger the memories supporting the skill, and effectively hangs in suspended animation until the environment provides the cues needed for retrieval of a given response-pattern. Trainers of apes have had to cope precisely with this limitation; for instance, it often takes thousands of trials to establish a reliable signing response in a chimpanzee (Greenfield & Savage-Rumbaugh, 1990). …”