In the United States during the past ten years, there has arisen a very favorable environment for those interested in the retarded child. Effective and energetic parent organizations have exerted a progressive influence on governmental agencies. Special educational facilities have expanded in number and scope. Urban universities have become involved, some even committed, to the study of retardation. Federal funds, albeit recently restricted, have been readily available for research, training, and patient care.
The climate has also been intellectually stimulating for research, which has made great progress especially in cytogenetics and inborn errors of metabolism. There is ample evidence that basic research aids our understanding of the retarded child, and that clinical research in retardation has stimulated the investigation of fundamental biological phenomena.
In this small volume, some of the recent work of contributors to progress in the general area of mental retardation has