This study examined the performance of middle aged and elderly adults on the Piagetian tests of class inclusion and multiple classification. (GO)

Formal and familiar materials were used to test Piagetian classification and formal operational abilities in two groups of educated adults: one group aged 30-38 and the other aged 57-82 years. Subjects did not show mastery of the tasks. Results suggest a new model of cognitive lifespan development. (Author/MS)

Although studies using recall tasks to measure memory typically report age-related declines in performance for older subjects, little is known about how these research results relate to performance in actual situations. A study was undertaken to determine whether years of experience in a domain of knowledge could compensate for age-related…

Few studies concerning siblings have taken a lifespan approach, i.e., studying sibling relationships from childhood to old age. To outline the developmental changes that occur in the quality of the sibling relationship during various periods of the life cycle and to test the feasibility of devising a coding system to identify such changes, 47…

A dual taxonomy is presented to reconcile two incongruous facts about antisocial behavior, that it shows impressive continuity over age, but its prevalence changes dramatically over age, increasing almost tenfold during adolescence. Studying delinquents earlier in life may yield more information about the causes and antecedents of antisocial…