Investigations of the Behavior of Paramecium Aurelia: III. The Effect of the Presence and Absence of Light on the Occurrence of a Response

This study was designed to evaluate how a series of measures made on 77 infants at ages 3, 6, 9, 12, 18, and 24 months could be used to predict measures made at about 5 years of age. The analytical procedures were selected to be sensitive to differences among individuals in the function that relates test performance to age. Neither evidence for such heterogeneity nor incremental validity of the measures made at 18 months and earlier was obtained. It is concluded that the Gesell Developmental Schedule, the Cattell Infant intelligence Scale, and the California Infant Scale of Motor Development, administered at 18 months and earlier, are invalid both as static indicators of later performance and as dynamic indicators of development.