Abstract
Assessment of 180 college students at three ages, 17–23 years, 37–43 years, and 61–80 years, examined (1) the relative availability of Piagetian formal reasoning concepts, (2) the relationship of these formal reasoning performances to Horn and Cattell’s psychometric theory of general fluid and crystallized intelligence, and (3) developmental patterns among standardized intelligence tests, logical reasoning, immediate memory span, and selected personality or cognitive style measures. Total sample oblique factor rotation yielded 5 factors: (1) general fluid ability with significant loadings for matrices, field independence, and the 9 formal reasoning variables, (2) personality, (3) immediate memory, (4) verbal ability, and (5) internal locus of control. Factor pattern differences found in gender and age group analyses suggested caution in interpreting age main effects. Formal reasoning performances were generally adequate for all individuals including the elderly. Field independence was the best single predictor of formal reasoning which appeared to be more closely related to general fluid than to general crystallized intelligence measures.