The quantity of literature generated each year on the subject of infantile autism might lead one to believe that autism must be among the most frequent of disorders, although it occurs in only one of every 2500 children. Here is yet another book, but this volume distinguishes itself as a particularly useful review of what is new and interesting in the field. It is pleasing to find the names of so many creative young investigators among its contributors and to see their various ideas presented side by side in a single volume.
Roughly 70% of autistic persons are mentally retarded, and, like nonautistic retarded persons, they show varying degrees of impairment in learning vocabulary and grammar in their early years. Subsequently, they have difficulty mastering reading, writing, and arithmetic in school. Such cognitive deficits do not, however, in and of themselves, explain why someone is "autistic." A person is autistic,