title: Ontogeny and phylogeny of language.
abstract: How did language evolve? A popular approach points to the similarities between the ontogeny and phylogeny of language. Young children's language and nonhuman primates' signing both appear formulaic with limited syntactic combinations, thereby suggesting a degree of continuity in their cognitive abilities. To evaluate the validity of this approach, as well as to develop a quantitative benchmark to assess children's language development, I propose a formal analysis that characterizes the statistical profile of grammatical rules. I show that very young children's language is consistent with a productive grammar rather than memorization of specific word combinations from caregivers' speech. Furthermore, I provide a statistically rigorous demonstration that the sign use of Nim Chimpsky, the chimpanzee who was taught American Sign Language, does not show the expected productivity of a rule-based grammar. Implications for theories of language acquisition and evolution are discussed.
authors.affiliation: Department of Linguistics and Computer Science, Institute for Research in Cognitive Science, University of Pennsylvania, Philadelphia, PA 19081, USA. charles.yang@ling.upenn.edu
authors.forename: Charles
authors.initials: C
authors.lastname: Yang
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003071:Cognition / Q000502:physiology*; D006801:Humans; D007804:Language Development; D008037:Linguistics / Q000379:methods*; D008962:Models, Theoretical; D010802:Phylogeny; D011323:Primates / Q000502:physiology*; D013045:Species Specificity