Individual differences in language development: Implications for development and language.

Differences in characteristics of language development that have been identified in a number of recent studies are reviewed. In these studies, some children have been found to emphasize single words, simple productive rules for combining words, nouns and noun phrases, and referential functions; others use whole phrases and formulas, pronouns, compressed sentences, and expressive or social functions. The evidence for two styles of acquisition and their continuity over time is examined. Explanations in terms of hemispheric functions, cognitive maturation, cognitive style, and environmental context are considered, and an explanation in terms of the interaction of individual and environment in different functional contexts is suggested. Implications for development and the mastery of complex systems are discussed. A new consensus is emerging about the appropriate framework within which to view the important problems of language acquisition. In contrast to the prevailing view a decade ago that language development could only be understood within a linguistic, genetic, rule-testing, individual framework, students of child language today have increasingly accepted the premise of a developing social, cognitive, and communicative system within which language is gradually mastered. The implications o f this shift for our view of both language and development are important, as the burgeoning literature in the journals and in such recent edited collections a s Collins (1979), K . E . Nelson (1978, 1980), and Lock (1978) indicate. A sense o f the richness and interest o f the newer approaches can be gleaned from these sources. Here I would like to consider how the study of individual differences in development fits into this new framework and adds to it. Research reported in this article was supported in part by a grant from the Carnegie Corporation of New York. I would like to thank Ellen Tanouye for her valuable contribution to data collection and transcription and