Call for a follow-up study of experiments on long-term deprivation of human infants.

Three experiments on long-term isolation and educational deprivation of infants were performed 50 years ago by Myrtle McGraw and by Wayne and Marsena Dennis. Current textbooks regularly present these studies incorrectly as supporting the notion that early motor development is unaffected by environment. This presentation is shown to be incorrect by a reanalysis of the studies which indicates severe and far-reaching negative effects of the depriving conditions upon the experimental infants. A follow-up study of the experimental subjects in later years and a publication of McGraw's unreported study are called for.