Relational integration in working memory and children's fluid intelligence

Both cognitive and developmental literatures report strong relationships between working memory and fluid intelligence. However, few authors integrate these data in a theoretical model of intelligence development in children. The Relational Complexity Theory provides a theoretical framework: (a) to understand how the working memory capacity could influence relational induction, which in turn constitutes a central mechanism of intelligence and (b) to create experimental tasks dedicated to the assessment of relational integration capacity. In the present study, children aged 9 to12 years were administered three tasks: a task assessing fluid intelligence, a classical working memory task, and a new task specifically designed to assess relational integration capacity. Results indicate that age-related changes in fluid intelligence are mediated by the growth of relational integration capacity, beyond the contribution of concurrent storage and processing. The discussion reexamines the respective roles of working memory functions in reasoning as well as methodological issues in their study.