The development of children's understanding of "because" and "so"

Children's (5 years, 8 months to 8 years, 4 months) comprehension of "because" and "so" was assessed on both enactment and sentence completion tasks. The use of a within-subject design permitted performance on each task to be interpreted in terms of performance on the other. The pattern of results provided evidence against a componential model for the acquisition of causal connectives. This model holds that the two meaning components (cause, order) are acquired separately, with the order component being acquired several years later than the causal component. The results also were in accord with predictions derived from a contextual model of children's developing understanding of terms expressing logical relationships. This model posits that the understanding of relational terms is initially context dependent, such that children can understand relational terms when they express familiar relationships, but experience difficulty in forming representations of novel relationships solely on the basis of linguistic input. The lexical components of because and so are understood during the context-dependent stage, and the transition from context-dependent to context-independent understanding does not reflect further lexical development, but rather increasing facility in dealing with decontextualized linguistic input.