Goals: This study examined: (a) crystallized/fluid intelligence trajectories of adolescents and adults with Down syndrome; and (b) the contribution of endogenous (health, activities of daily living--ADL) and exogenous (cognitively stimulating leisure activities) factors on adults' intelligence with age. Method: Four cohorts (N = 80) with Down…

Examined the contributions of Task Uncertainty and Perceptual Cohesiveness to changes in block design performance in older adults (N=83). Results showed performance changed significantly over the age span as a function of Task Uncertainty but after age 49 performance was not affected by Perceptual Cohesiveness. (JAC)

Studied strategy development in a computerized task developed from the block design task of S. Kohs (1923). Results for 90 subjects aged 12, 17, and adult show 3 strategies: global, analytic, and "synthetic." Discusses some age differences and implications for recent work in cognitive and developmental psychology. (SLD)

Three experiments investigated the possibility that adult age differences on block design tasks originate because of reduced efficiency with increased age in the cognitive processes associated with block manipulation. Older adults were substantially slower and less efficient than younger adults in performing tasks with minimized design…