"Although recognized since antiquity, explanations of the nature, causes, and treatment of intellectual and developmental disabilities have varied considerably. Historically, the earliest reference and discussion of intellectual developmental impairment may be in the Egyptian Papyrus of Thebes circa 1552 B.C. (Bryan, 1930). Over the intervening centuries, there has been considerable confusion about the nature and meaning of intellectual and developmental disabilities. Approaches to intervention have ranged from infanticide to exorcism and removal of evil spirits to humane education. In Greek and Roman culture, infanticide was practiced and trephining may have been used in Europe, Central, and South America as a treatment, presumably to allow such spirits to escape. Some intellectually impaired people may have become slaves and others court jesters.

In the Middle Ages, demon possession continued to be suspected, but adequate care was practiced as well, for example, in the famous Hospice in Gheel, Belgium. An intellectually impaired child might also have been regarded as a changeling - an unusual child who was substituted at birth for a normal child by the fairies. In some instances, intellectually impaired people were regarded as "children of God" or harmless innocents who were allowed to wander at will. Based on this more benign view, Henry II of England promulgated legislation to provide for their protection. "Natural fools" were made wards of the king (Deitz and Repp, 1989)"--.