“Ontogeny and Phylogeny of Language”, 2013-04-01 ():
[video] 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. [ie. Chimpsky only learned 2-gram/bi-gram language models]
Implications for theories of language acquisition and evolution are discussed.