Language and communication problems have long figured prominently in the definition of mental retardation. Volume 27 of the International Review of Research in Mental Retardation focuses exclusively on these language and communication issues. The pace of research on language learning and use in mental retardation has increased in recent years and taken new direction. This revitalization has been fueled by three factors: 1) advances in genetic technologies allowing investigation of the behavioral phenotypes of well-defined syndromes, 2) an increased emphasis on maximizing abilities...