The paper notes A. Hore and W. Tryon's support of the developmental position that persons with and without mental retardation of similar mental age show similar cognitive patterns, but suggests that mental age is psychometrically invalid and Piagetian tasks are inappropriate to evaluate this position. An information processing approach is…

Findings of three studies indicate that young children with Down syndrome perform similarly to typical controls matched on mental ages (MAs) of approximately 3 years. However, by developmental age of 4 years, children with Down syndrome performed worse than both MA-matched typical children and children with non-Down syndrome types of mental…

The performance of 25 children with Down syndrome (DS) on delay of gratification tasks was compared with that of mental age-matched typically developing children. DS children were significantly less able to delay gratification on two of the three tasks. Results raise questions about using mental age as the method for matching children with DS and…