A CROSS-SECTIONAL ANALYSIS OF WAIS-R AGING PATTERNS WITH PSYCHIATRIC-INPATIENTS - SUPPORT FOR HORN HYPOTHESIS THAT FLUID COGNITIVE-ABILITIES DECLINE

WAIS-R aging patterns were examined for a group of 200 psychiatric inp atients. Inpatients were grouped into six age categories: less than 24 , 24-28, 29-32, 33-38, 39-43, and greater than 43 years. Verbal and Pe rformance sums of scaled score, subtest scaled score, and raw score to tal, and individual item score means were examined for each age catego ry. The classical aging pattern was observed wherein more crystallized cognitive abilities remained stable over age groups of the life span while more fluid abilities dropped sharply with their increasing ages. Results supported the decline in fluid cognitive abilities hypothesis for WAIS-R aging patterns advocated by Horn in 1985 and Kaufman in 19 90.