Contributions of the Individual Differences Approach to Cognitive Aging.

Objective: To review selected research in cognitive aging incorporating an individual differences approach.

Method: Three contributions of the individual differences perspective in cognitive aging are illustrated with data from the Virginia Cognitive Aging Project.

Results: Research capitalizing on the variability among individuals has been used to: (a) improve sensitivity and validity of measurement of cognitive functioning, and evaluate possible age differences in the meaning of the measures; (b) investigate relations between age and individual cognitive measures in the context of other types of cognitive measures; and (c) examine the degree to which age-related influences on target measures are statistically independent of age-related influences on other cognitive measures.

Discussion: Although the primary focus of much of the research in cognitive aging has been on mean differences between people of different ages, people differ in many respects besides age. A fundamental assumption of the individual differences perspective is that at least some of those differences may be informative about the nature, and causes, of the relations between age and cognitive functioning.