How children develop their ability to combine words: a network-based approach

© The Author(s) 2019. A new way to study and represent early syntactic development is introduced that offers a promising avenue to improve on standard cumulative approaches to language learning. The analysis is inspired by complex network theory and explores an important issue in psycholinguistics: how children combine words syntactically. To this end, the article exploits the longitudinal data of multiple individual studies stored and publicly available in the CHILDES database. This analysis proves useful in two regards: in coincidence with previous approaches to syntactic development, it reveals a similar linear–nonlinear pattern of syntactic development (a combination of linear periods interrupted by abrupt transitions) in typical children regardless the language they are acquiring. It also provides a straightforward objective measure of syntactic impairment in atypically developing children. A striking difference between typical and atypical children lies in the connectivity of functional words, which suddenly become hubs but only in typical development. Our technique offers a formal measure of impairment with respect to typical syntactic development, which goes beyond the standard notion of retardation in development, for the Down syndrome condition.