It is argued that external validity across situations and life stages cannot be obtained for any single measure of intellectual ability. Presented at 84th Annual Meeting of the American Psychological Association, Washington, 1976. (Author/PD)

Cohort-sequential analyses were conducted on measures from the Primary Mental Abilities Test and the Test of Behavioral Rigidity for 2,151 participants at the first testing and 723 individuals at the retesting 7 years later. Data were examined for 7-year age intervals from 25 to 81 years and cohort intervals from 1889 to 1938. (Author/JMB)

Specifications are offered for a stage theory of adult cognitive development. Current psychometric technologies are criticized as being limited in descriptions of cognitive function. The development of novel technologies is suggested for study of adult cognitive development. Paper presented at the 10th International Congress of Gerontology,…

This reply to Horn and Donaldson is previous critique of Schaie and Baltes' Research and writings on intelligence in adulthood and old age has two parts: the first discusses theoretical perspectives and the second makes observations on the empirical data base. (Author/AM)

The basic issue underlying this research is whether or not adult personality structures change after maturity is reached. Problems involved in the longitudinal study of psychological variables are discussed and 2 feasible designs applied in an effort to differentiate the effects of chronological age, secular trends, generation differences, as well…

A major issue concerning adult intellectual development is whether intellectual decline in late adulthood is uniform or ability-specific. Differential patterns of ability decline were analyzed by comparing data on longitudinal age change over the age range from 53 to 81 years from two successive 14-year periods (1956-1970 and 1970-1984). The…

Summarizes the conduct and results of the Seattle Longitudinal Study, an investigation that has assessed mental abilities in more than 5,000 adults and has followed some for as long as 35 years. Integrative findings are presented on age changes, cohort differences, factor structure, individual differences, and interventions. (SLD)