This article reports individual differences analyses of performance on list and prose memory tasks for 250 men and 258 women aged 55-84. Being retested, higher reasoning and vocabulary scores, and female gender predicted better prose recall and list recognition performance. For list recall, retest status, age, years of schooling, and gender, as well as reasoning and vocabulary, were reliable independent predictors. After 3 years, 106 men and 121 women returned for a retest. Analysis of individual differences in 3-year performance indicated that, once Time 1 performance had been partialed, individual change could be predicted by age or reasoning, but neither variable uniquely accounted for change. Analysis of data of individuals who experienced considerable decline or improvement in 3-year scores indicated that decline was consistently associated with advanced age. Ramifications for theoretical models in memory research are discussed.

This article distinguishes between normal and pathological aging, provides an interdisciplinary context, and then considers a sample case of cognitive aging. Developmental influences on cognition include the physiological infrastructure, genetic predispositions, and environmental influences. Different types of longitudinal studies are distinguished, and contrasting findings of cross-sectional and longitudinal are examined in the sample case of the Seattle Longitudinal Study. Also considered is the longitudinal context for intervention studies and the role of longitudinal family studies in assessing rate of aging and generational differences in rates of aging. Finally, attention is given to the role of longitudinal studies in the early detection of risk for dementia in advanced age.In this article I distinguish between normal and pathological aging, provide some historical context, discuss shifts in relevant methodological paradigms, provide an interdisciplinary context, and then consider a sample case of cognitive aging in greater detail.A distinction is made between age related declines that should be attributed either to neuropathology or to disuse and obsolescence. But aging can also be considered as development in domains such as experience and wisdom, and we must distinguish between successful and unsuccessful aging.The study of adult development originated in the early mental testing movement. Crosssectional findings of substantial age-related declines from early to late adulthood soon motivated the development of longitudinal studies. Other methodological paradigm shifts of importance to longitudinal inquiry have involved advances in the measurement of age, confirmatory factor analysis, and treatment of age as the dependent variable.I then present a model that considers the roles of age-related changes in the physiological infrastructure, genetic predispositions, and environmental influences. Different types of longitudinal studies are distinguished, and contrasting findings of cross-sectional and longitudinal studies are examined in the sample case of the Seattle Longitudinal Study.Selected findings from this study are presented to discuss the complex interaction of longitudinal age changes and cohort differences. The latter introduces the role of longitudinal family studies in assessing rate of aging and generational differences in rates of aging. Also, I briefly consider the longitudinal context for intervention studies designed to slow the rate of aging.And, finally, I discuss the role of longitudinal studies in the early detection of risk for dementia in advanced age, which involves linkages between studies of normal and pathological aging as well as attention to genetic markers of dementia.Requests for reprints should be sent to

The relationship between cognitive function and survivorship was examined in a community-dwelling sample. Survival analysis was used to examine how level and change in intellectual functioning, verbal memory, perceptual speed, and psychomotor speed were related to mortality in a sample of 601 individuals who subsequently died (decedents; n = 342 men; n = 259 women; M = 73.81 years of age) and a control group of 609 survivors (n = 296 men; n = 313 women; M = 71.96). The sample of survivors was selected to be of similar age and to have a similar level of education as the decedents. Individuals in the lowest 25th percentile of performance (crystallized abilities, visualization abilities, verbal memory, and perceptual and psychomotor speed) had a significant risk for subsequent mortality compared to individuals in the highest 25th percentile. However, after adjusting for demographic variables and psychomotor speed, only perceptual speed remained a significant risk factor for mortality. Significant 7-year declines (lowest 25th percentile) in measurements of Verbal Meaning, Spatial Ability, Reasoning Ability, and Psychomotor Speed were risk factors for subsequent mortality relative to those who had the least amount of decline. The relationship between mortality and cognitive function tended to be a specific rather than a pervasive phenomenon, even after adjusting for sociodemographic factors and psychomotor speed. Decrease in cognitive performance tended to be a better predictor of subsequent mortality than was the level of cognitive performance.

Previous cross-sectional and longitudinal studies of age changes over the adult life span have reported contradictory age gradients. The apparent contradiction was assessed by means of a new research design, called the crosssequential method, which involves the repeated measurement of members of a cross-sectional sample. The SRA Primary Mental Abilities Test (PMA) and Schaie's Test of Behavioral Rigidity (TBR) were administered to a stratifiedrandom sample of 500 5s with quotas of 25 men and 25 women in each 5-yr. age interval from 20 to 70 yrs. 7 yr. later all 5s who could be located were contacted and 302 5s were retested. Significant cross-sectional age changes were found for all variables studied, but longitudinal age changes occurred for all cohorts only for those variables where response speed was of importance. Analysis of the comparative age gradients suggests that age changes over time within a given individual appear to be much smaller than differences between cohorts and that the steep textbook age gradients represent no more than the effects of increased environmental opportunity and/or genetic changes in the species. Further implications with respect to revisions in current thinking on adult age changes are discussed.

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