ABSTRACT
When viewed from the perspective of the theory that has been developed in the present volume, cognitive development appears to be remarkably synchronous, at least in middle childhood. At each of the four modal ages of the dimensional stage, most children demonstrate parallel performance across a broad array of tasks, including those that tap the same underlying conceptual structures, and those that tap different ones. Although asynchronies in functioning across such tasks are not uncommon, they appear to be limited to one substage in the great majority of cases (Case, Marini, et al., 1986; Case, Griffin, McKeough & Okamoto, this volume, chapter l5).
