The Ontogeny of Scale-Free Syntax Networks through Language Acquisition

The evolution of human language allowed the efficient propagation of nongenetic information, thus creating a new form of evolutionary change. Language development in children offers the opportunity of exploring the emergence of such complex communication and is considered as a window to the transition from protolanguage to language. Here we analyze available information from the CHILDES database and we study the emergence of syntax in terms of complex networks where words are connected through syntactic links, providing a global view of the organization of syntactic relations. A previously unreported, sharp transition is shown to occur at ≈ 2 years from a tree-like structure to a scale-free, small world syntax network. The nature of such transition supports the presence of an innate component pervading the emergence of full syntax.