Continuity, discontinuity, and atypicality in early language acquisition

Continuity and discontinuity during the development from infancy to later stages are central themes in developmental psychology. These concepts are particularly important for understanding and supporting language development in children with atypical language development. This review aimed to clarify future research issues on the early language acquisition process up to 36 months of age from the viewpoint of developmental continuity and discontinuity in early language acquisition. Recent studies on early language development support the concepts of both continuity and discontinuity, particularly in the relationship between early gestural development and later language acquisition, as well as in predicting delayed speech in children. However, focusing on 24 months of age, when the development of syntax typically begins, several studies have reported relationships between developmental domains such as gross motor and language. It is necessary to examine continuity and discontinuity in the early language acquisition process from an interdisciplinary perspective. Furthermore, it is important to consider both the speeding up and slowing down aspects of developmental trajectories in early language acquisition. Research on the language acquisition of late bloomers is important from the viewpoint of continuity and discontinuity from the prelinguistic period, domain relevance, and speed in cognitive development.