Patterns in the Emergence of Hand Actions in Typically Developing Infants

Abstract

Purpose: The dynamic systems theory regards the development of an infant as a complex and dynamic system. This study investigates the development of the hand system in typically developing infants, in the backdrop of this theory. Specifically, we wanted to document the growth trajectories exhibited by these behaviours within the first year of life and to determine a predictable age at which these hand actions would exhibit a change in occurrence, in the face of variability. Method: Nine typically developing infants, 3 females and 6 males, were videotaped from the third month till they turned twelve months of age, while interacting with their mothers. Samples were coded for the occurrence of four categories of hand actions (actions during play/rest; actions with objects; actions towards adults; iconic actions) using ELAN. Results: The hand actions we studied were marked by variability as evidenced in their growth trends, and some of these hand actions, especially those that help manipulate objects and those seen during play/rest demonstrated an age at which reliable change in the rate of occurrence was seen within the developmental period. Conclusion: Our results demonstrate that the development of the hand system follows some principles of being a dynamic system.