Mabel L. Rice
Steven F. Warren
University of Kansas
The investigation of language impairments in children has an extensive record. With the exception of the condition now classified as specific language impairment (SLI), much of the literature has focused on the clinical conditions in which language impairment appears as a concomitant condition, such as Down syndrome, Williams syndrome, mental retardation, autism, and, more recently, fragile X syndrome. Funding for research and the associated culture of review has, within the United States at least, been defined more by the clinical categories than the common elements of language impairment. This separation of effort has led to important and fundamental discoveries and has had many advantages, not the least of which is the successful advocacy of funding according to diagnostic category.
This approach to scholarship is less effective in the modern era because advances in genetics necessitate precision in the measurement of the behavioral phenotypes, and the fact that language impairments cross many diagnostic categories and can obscure the genetics of intellectual impairment, social competencies, or other related attributes. Furthermore, language is a key predictor of developmental outcomes and a salient way for families to note affectedness. New insights about genetic effects bring increased recognition of the finely tuned interactions of neurocortical, genetic, and behavioral elements of inherited factors, and the role of environmental events such as intervention. On the other hand, new developments in linguistic theory and application to children with language