Origins and development of representational systems in early childhood
It is argued in Chapters 1 to 4 that in cognitive psychology in general, and in the disciplines of language acquisition and cognitive development in particular, there is substantial benefit to be derived from distinguishing between two representational systems, one system being deployed in long-established or highly-practiced functions, and the second deployed in novel tasks, or where difficulties interrupt the first system. It is also argued that the proper subject of cognitive development is the second of these systems. Chapters 5 and 6 are concerned in different ways with the origins of language in the individual, in particular with the question of what innate knowledge of language might be justified. It is concluded that many questions regarding innate knowledge remain open, and that a source in human evolution for knowledge of language is no more likely than sources in individual or social development. In Chapter 7 it is argued that representational drawing emerges late in the 4th year of life, and some new techniques are described for studying early representational drawing. Following these treatments of external systems of representation, Chapter 8 offers a general developmental theory of forms of representation, extending Piaget's insight that mental representation is co-extensive with thought, and that the main axis of cognitive development is the content of thought and representation. Chapters 9 to 12 apply this theory to the representation of belief and desire, and of extrinsic and intrinsic qualities of objects, by 11/2 to 4 year-old children. Chapter 13 introduces a new method for analyzing the free classification task, a task sometimes used to assess children's ability to think about intrinsic qualities, and applies this method to various data sets. Chapter 14 applies these insights and results to the problem of characterizing concepts and concept development and favourably discusses the idea that more precise knowledge of this aspect of development may help to explain certain features of early language acquisition.