Progress in cognitive science requires a balance between divergence and convergence of approaches. As an interdisciplinary and integrated field for scientific understanding of the human mind, cognitive science has incorporated diverse approaches such as computer modelling and brain imaging. These approaches have brought us not only new findings but also new problems when the findings of different approaches are in conflict with each other. For example, advances in infant looking-time methodologies (e.g. Baillargeon, 1986; Ahmed and Ruffman, 1998) have led to claims that infants know far more about the physical world than previously credited by studies using more traditional methodologies (Piaget, 1954). The current novel emphasis on electrophysiological methodologies, such as electroencephalogram (EEG) or evoked response potential (ERP), adds another layer of complexity. As a result, cognitive scientists have had to develop new models of the mind that can integrate empirical evidence across multiple methodologies (e.g. Munakata, 2001) in order to converge on a unified model of cognitive functioning.

The five chapters of Part II are a case in point. These chapters all address questions of when and how infants and young children acquire representations of the bodies of other people. The chapters are remarkably diverse; there are several important distinctions that cut across the chapters and that highlight the fact that representing others’ bodies is a complex, multi-layered cognitive process.