A CHC Theory-Based Analysis of Age Differences on Cognitive Abilities and Academic Skills at Ages 22 to 90 Years

Age differences for nine age groups between 22 and 25 years and 81 and 90 years were evaluated, covarying educational attainment, on five Cattell-Horn-Carroll (CHC) abilities: fluid reasoning (Gf), crystallized ability (Gc), quantitative knowledge (Gq), reading (Grw-Reading), and writing (Grw-Writing). Data were from the adult portions of the stratified standardization samples of the second editions of the Kaufman Brief Intelligence Test (N = 570) and the Kaufman Test of Educational Achievement-Brief Form (N = 555). Gc and Grw-Reading were maintained through old age, whereas Gf, Gq, and Grw-Writing were vulnerable abilities. The age-related decline in mean scores on Gf was powerful, as even the maintained CHC abilities of Gc and Grw-Reading proved to be vulnerable when the component tasks of each were analyzed separately. All Gender x Age interactions were nonsignificant, indicating that age differences for all CHC abilities studied were essentially the same for men and women.