A central controversy in developmental science, enflamed by nativist accounts, is whether development is best viewed as a series of qualitative or continuous changes. This article defends the notion of qualitative change from the perspective of dynamical systems theory (DST). Qualitative change within DST refers to the shift that occurs when a…

Nativist and constructivist approaches to the study of development share a common emphasis on characterizing beginning and end states in development. This focus has highlighted the question of preservation and transformation--whether core aspects of the adult end state are present in the earliest manifestations during infancy. In contrast, a…

This paper is in memory of Esther Thelen, who passed away while President of the Society for Research in Child Development. A survey of Esther Thelen's career reveals a trajectory from early work on simple movements like stepping, to the study of goal-directed reaching, to work on the embodiment of cognition, and, ultimately, to a grand theory of…