| Abstract: | Eighty subjects from a larger number of participants in a longitudinal study were selected according to their 1916 Stanford-Binet Intelligence Test scores, administered in the 1930s, and their 1977 occupations. They were then individually administered the Wechsler Adult Intelligence Scale. The research questions asked were: Did subjects shift their positions relative to age peers with regard to measured intelligence from Time 1 (1930s) testing to Time 2 (1977) testing? And, if they did, were these shifts related to their occupational levels? A secondary question asked whether subjects as a group showed mean T score increments between test times. A Pearson correlation coefficient (r = .62) showed that subjects had significantly maintained their positions relative to peers with regard to measured intelligence over approximately one-half of a century. The hypothesis that persons in higher level occupations should show greater gains in measured intelligence over time was not supported. Using multiple regression procedures, no significant difference was found from analysis of effects of occupational level on D (D = T2 ? T1) scores. An 80-subject mean T score increase (M = +8.13) was found. This represented an average increase of four-fifths of a standard deviation in T score units. These data suggest that, on average, persons increase in mental abilities over time while maintaining IQ positions relative to peers and that those changes in IQ which do occur are not related to occupational level experience. |
