Ability Factor Structure Differences In Adulthood And Old Age

Simultaneous maximum likelihood procedures were used in investigate age differences in ability factor structure in adulthood. Data were analyzed for 198 young individuals (age range of 15-32 years), 173 younger old individuals (age range of 51-67 years) and 153 older-old individuals (age range of 68-83 years). Variables were fourteen ability tests marking five cognitive factors: Verbal Comprehension, Number Facility, Perceptual Speed, Symbolic Cognition, and Flexibility of Closure. Results indicated no change in the number of factors and no important shifts in salient loadings. The magnitude of factor covariances, however, tended to increase across age groups. Such shifts were not uniform across factors but appeared to be dependent on the properties of different factors as to whether factor covariance increases were early or late. The results suggested an increasing interdependence of intellectual functioning in late life.