Abstract
This paper discusses Esther Thelen's developmental theory from the perspective of motor development, as rooted in George E. Coghill's embryologic research and as developed by Arnold L. Gesell and Myrtle B. McGraw. A comparison of the developmental theories and research of Gesell, McGraw, and Thelen clarifies two theoretical fundamentals and two future subjects of interest regarding motor development. The two fundamentals are that: (i) the entire system's behavior is analyzed in terms of interactions among sub-systems, and (ii) developmental change triggers are specified in relation to the status of the system and sub-systems. Future subjects include: (iii) the concept of intrinsic dynamics, which indicates how a system's intrinsic state affects its development, and (iv) multiple time scales, which indicate that changes of various time scales are nested in development. We verified points (iii) and (iv) based on recent studies that propose future issues for consideration in the study of motor development.
