Do houseflies think? Patterns of induction and biological beliefs in development

A current debate within the cognitive development literature addresses how best to characterize conceptual change, Within one proposal, development primarily consists of a series of radical conceptual shifts or restructurings in which the most current understanding is inexplicable within (incommensurate with) prior conceptual structure. Alternatively, development is discussed as more gradual enrichment of multiple existing early explanatory systems, allowing for commensuarability over time and change. This paper examines the literature in this debate with specific focus on naive biological understanding, and discusses a series of studies on preschoolers' inductive inferences across biological and non-biological kinds. Children were taught a series of biological properties for a human being (e.g. eating, sleeping etc.), and asked to generalize these properties to both biological (e.g. dogs, worms) and non-biological kinds (e.g. clouds, tables). The results of these studies support the gradual enrichment proposal. Specifically, 4-year-olds seem to possess a limited, but coherent and independent biological theory which may form the basis of mature understanding of biological kinds. These results are discussed in terms of multiple explanatory systems which both preschoolers and adults can employ across development to effectively guide their decisions within a given domain. (C) 1998 Elsevier Science B.V.