What, when, and how about why: a longitudinal study of early expressions of causality.

Children's expressions of causality in natural discourse with adults were examined in terms of linguistic, contextual, and pragmatic influences. Specifically, the causal statements, questions, and responses to causal questions of eight 2-3-year-old children were examined in terms of developments in language content, form, and use. With respect to content, the referential and functional uses of causal expressions for both children and adults were to ongoing or imminent situations, with the speaker commenting on his or her intention to act, or requesting the listener to act. The major categories of reference in all three utterance types were negation, direction, and intention. In terms of form, there were (a) increasing use of connectives to link clauses for all the children, and (b) three main patterns of clause order differentiating among the children: cause/effect, effect/cause, and equal use of both orders. The use of expressions of causality developed in the order: child statements less than adult questions less than child responses less than child questions. The relationship of the linguistic context to these developments was found to be one of mutual influence between child and adult. The results are discussed in terms of previous hypotheses concerning (a) causal reasoning (especially those put forth by Piaget, and by Werner & Kaplan in 1963), (b) the relationship between language and conceptual development, (c) the constraints involved in different discourse situations, and (d) variation in child language.