Cognitive development in the Down's Syndrome infant: slow or different?

Abstract

Summary. An investigation was carried out to determine whether cognitive development in the Down's Syndrome (DS) infant is identical in nature with that of the Normal (N) infant, even though manifesting a general retardation. Longitudinal investigation was carried out of Object Permanence development in a group of 8 DS infants and a group of 26 N infants. As expected, DS infants manifested delayed achievement of all steps in the sequence. In addition, however, DS infants were less likely than N infants to repeat an achieved success on the following test session. Further, and in contrast to the N infants, errors committed by the DS infants tended not to conform to the “characteristic” error pattern theoretically predicted for each task. It was concluded that identity in development across the two populations holds at the level of first achievement only. Cognitive development in the DS infant must be considered not merely “slow” but rather, in important respects, different from that in the normal infant.