STRUCTURAL EQUATION MODEL OF INTELLECTUAL CHANGE AND CONTINUITY AND PREDICTORS OF INTELLIGENCE IN OLDER MEN

This study examined the effects of abilities as a young adult, an enga ged lifestyle, personality, age, and health on continuity and change i n intellectual abilities from early to late adulthood. A battery of me asures, including a verbal and nonverbal intelligence tests, was given to 326 Canadian army veterans. Archival data provided World War Two e nlistment scores on the same intelligence test for this sample. Result s indicated relative stability of intellectual scores across 40 years, with increases in vocabulary and decreases in arithmetic, verbal anal ogies, and nonverbal skills. Young adult intelligence was the most imp ortant determinant of older adult performance. Predictors for verbal i ntelligence were consistent with an engagement model of intellectual m aintenance but also indicated the importance of introversion-extravers ion and age. Nonverbal intelligence in late life was predicted by youn g adult nonverbal scores, age, health, and introversion-extraversion.