Ontogeny and phylogeny of language

Area of Science:

• Evolutionary Linguistics
• Developmental Psycholinguistics
• Primate Communication

Background:

• Theories of language evolution often compare child language acquisition (ontogeny) with language development in ancestral species (phylogeny).
• Similarities in early child language and non-human primate communication suggest shared cognitive foundations.
• Existing research lacks quantitative methods to assess the grammatical productivity in these comparisons.

Purpose of the Study:

• To formally analyze the statistical profile of grammatical rules in early language.
• To establish a quantitative benchmark for assessing language development in children.
• To evaluate the continuity hypothesis by comparing child language with primate sign language.

Main Methods:

• Formal statistical analysis of grammatical rule structures.
• Characterization of the productivity of language use in young children.
• Rigorous statistical assessment of sign usage by a chimpanzee (Nim Chimpsky) taught American Sign Language.

Main Results:

• Very young children's language exhibits characteristics of a productive grammar, not mere memorization.
• The sign use of Nim Chimpsky did not demonstrate the expected productivity of a rule-based grammar.
• Quantitative analysis provides a benchmark for distinguishing genuine grammatical productivity.

Conclusions:

• Early child language development supports the existence of innate, productive grammatical abilities.
• The comparison with primate sign language challenges the notion of direct cognitive continuity in language evolution.
• Findings have significant implications for theories on language acquisition and the evolutionary origins of language.