Private speech use in arithmetical calculation: contributory role of phonological awareness in children with and without mathematical difficulties.

The majority of recent studies conclude that children's private speech development (private speech internalization) is related to and important for mathematical development and disabilities. It is far from clear, however, whether private speech internalization itself plays any causal role in the development of mathematical competence. The main concerns of the present study were whether phonological awareness skills relate to private speech internalization, and whether the answer to this question changes with children's age and mathematical achievement levels. Comparisons were made between 67 children diagnosed with math difficulties and 67 children without math difficulties from Grade 2 to Grade 7 in primary schools. Two separate laboratory investigations were performed to explore children's developmental levels of private speech and phonological awareness, respectively. Analysis was based on private speech differences, phonological awareness differences, and differences in occurrence of private-speech/phonological-awareness category combinations. Children without math difficulties showed a grade-determined shift from less to more internalized private speech and from lower to higher levels of phonological awareness. In contrast, the development of children with math difficulties seemed almost to stop at the inaudible private speech/low level of phonological awareness combinations. Silence/high phonological level was the primary alternative for typical math achievers. Results are discussed in terms of directions for future research.