Introduction
Sensorimotor development occupies a special place in cognitive developmental theory. Infants' experiences through their motor activity in the first year or so of life are believed to contribute to their initial understanding of the physical world (e.g., Case, 1985). For this reason, sensorimotor development and cognitive development are inextricably related. Sensorimotor development holds an even greater significance for those using a cognitive approach derived from Piagetian theory in developmental studies of nonhumans, because only the first, sensorimotor period of cognitive development in the Piagetian scheme can be examined across species (e.g., Antinucci, 1989). In this chapter, I identify some limitations of a cognitively oriented approach to the comparative study of sensorimotor development. I also describe an alternative theoretical framework that I anticipate will better enable us to focus on the process of development, which many authors have urged (e.g., Fentress, 1984; Hinde & Bateson, 1984). The alternative framework, drawn from dynamical systems theory, is in a nascent stage, but I believe it holds great promise for comparative developmental studies.
A dynamical systems perspective allows us to examine the changing relations among elements in a system (say, walking) during development and the synchronic and diachronic links between the focal system and other systems (e.g., Fentress, 1986; Fentress & McLeod, 1986; Thelen, in press; Thelen, Kelso, & Fogel, 1987; Trevarthen, 1984a,b; Wolff, 1987).