Age-Related Differences in Mental Performance

Abstract

The effects of age and socioeconomic status on two sets of measures of cognitive performance were reviewed. One set consisted of the 12 subtests of the General Aptitude Test Battery; the other was a group of laboratory-based experiments, most of which were initiated by the late George A. Talland. The relationships among the various measures of performance within and between the two sets were examined. Finally, plans for future studies of age-related differences in cognitive performance were outlined. The four principal findings are as follows. (1) Age-related declines in performance were found in all subtests of the General Aptitude Battery. Performance declined least in those subtests where the effects of socioeconomic status were strongest and most in those subtests where socioeconomic status effects were weakest. There was no evidence for a significant interaction between the effects of differences in age and socioeconomic status. (2) It is more difficult for older individuals than for younger ones to (a) retrieve special information from short-term memory, (b) monitor two verbal sequences concurrently, and (c) initiate a response in a two-choice discrimination. Variations in performance on those tasks were not systematically related to socioeconomic status or education. (3) In both sets of measures, the major age-related differences in the level of performance were observed between subjects in their sixties or seventies and the younger ones. The largest age-related decrements occurred in tasks which were probably relatively unfamiliar in content or in form to the subject. (4) There was little overlap among the assessments of abilities represented by the General Aptitude Test Battery and the various Talland experiments.