Rethinking Disorders of Spoken and Written Language: Generating Workable HypothesesGrigorenko, Elena L. PhDJournal of Developmental & Behavioral Pediatrics: December 2007 - Volume 28 - Issue 6 - p 478-486 doi: 10.1097/DBP.0b013e31811ff895 Review Article Abstract Author Information ABSTRACT: Disorders of spoken and written language (DSWL) tend to overlap at multiple levels: manifestationally, procedurally, developmentally, and etiologically. In other words, these disorders exhibit a positive manifold of correlations expressed among their different procedural components and in prospective, concurrent, and retrospective comorbidity. There is no single accepted explanation for this positive manifold of correlations. The purpose of this article is to explore this multilayer overlap and to consider whether such a positive manifold can be explained by one or all of the three hypotheses delineated in the article. From the Child Study Center and Department of Psychology, Yale University, New Haven, CT. Address for reprints: Elena L. Grigorenko, PhD, Child Study Center and Department of Psychology, Yale University, 230 South Frontage Road, New Haven, CT 06519-1124; e-mail: Elena.Grigorenko@Yale.Edu © 2007 Lippincott Williams & Wilkins, Inc.