Transition from sensorimotor Stage 5 to Stage 6 by Down syndrome children: a response to Gibson.

Gibson (1978) has suggested that the transition from Sensorimotor Stage 5 to Stage 6 (i.e., the change from exclusive dependence on overt forms of representation and trial-and-error problem-solving to the beginning of internal representation and foresight in problem-solving) is particularly difficult for Down syndrome children. In order to test this "developmental wall" hypothesis, we compared longitudinally the performance of Down syndrome and nonretarded children on the Uzgiris and Hunt (1975) Object Permanence and Means-Ends Relations Scales. Results indicated that in contrast to Gibson's suggestion, the Down syndrome children progressed from Sensorimotor Stage 5 to Stage 6 at the same rate that nonretarded children did, once the generally slower developmental pace of the Down syndrome children was taken into account.