Studying the Perception-Action System as a Model System for Understanding Development, Volume 55, the latest release in the Advances in Child Development and Behavior series, includes chapters that highlight some of the most recent research in the field of development of the perception-action system, with an overarching theme of addressing how the development of the perception-action system is a useful model for understanding both typical and atypical development. Chapters in this latest release include discussions of Perception and Action, Exploration and Selection, and the Acquisition of Skills in Infancy, The Development of Object Fitting: The Dynamics of Spatial Coordination, Developmental Pathways of Change in Perceptual-Motor Learning, Timing Is Almost Everything: How Children Perceive and Act on Dynamic Affordances, Vision, Whole Body Coordinations, and the Development of Throwing, Action Errors: A Window into the Early Development of Perception-Action System, Are Different Actions Mediated by Distinct Systems of Knowledge in Infancy and Childhood?, Sensory-Motor Development as a Precursor to Cognition, and A Perception-Action Approach to Those with Developmental Coordination Disorder.