The Relationship Between 10-year Changes in Cognitive Ability and Subsequent Mortality: Findings from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) Trial.

Cognitive ability and cognitive decline are related to mortality in older adults. Cognitive interventions have been found to improve cognitive performance and slow cognitive decline in later life. However, the longitudinal effects of cognitive interventions on mortality in older adults remain unclear. Using twenty-year follow-up data from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial, we examined the association between cognitive trajectory (i.e., intercept, slope, and retest effect) and mortality, using shared growth-survival models. We evaluated the effect of ACTIVE cognitive training (memory, reasoning, and speed of processing) on mortality risk. Among the 2,802 participants, 2,021 died on or before the year 2019 (72.1%). Higher baseline, slower decline, and greater retest effects in general cognitive performance were associated with lower mortality risk after adjusting for covariates. Associations with mortality were similar contrasting general and domain-specific cognitive abilities. We did not observe any significant effects of ACTIVE cognitive training in memory, reasoning, or speed of processing on all-cause mortality. Our findings suggest cognitive training interventions do not have a significant effect on cognitive trajectory and mortality among older adults; rather, older adults with higher education tend to incur greater survival benefits from memory training.

Beyond Big Five trait domains: Stability and change in personality facets across midlife and old age.

OBJECTIVE: Accumulated evidence indicates both stable and malleable parts of inter-individual differences in the broad Big Five domains. Less is known, however, about stability and change at the more diversified facet level. With the current study, we fill this gap by investigating personality stability and change across midlife and old age. METHOD: We apply local structural equation measurement models and second-order growth curve models to four waves of data obtained with the full NEO Personality Inventory (NEO-PI-R) collected over 11 years from 1667 adults (Mage  = 62.69 years, SDage  = 15.62, 55% female) who participated in the Seattle Longitudinal Study. RESULTS: Measurement invariance analyses indicated that the psychometric properties of the NEO-PI-R facets are comparable across time and age. Results revealed substantial rank-order stabilities across all facets, yet the exact pattern varied strongly between facets of the same trait and across traits. Mean-level change of facets from midlife to old age largely mirrored the mean-level change observed for the broader traits. CONCLUSION: We discuss conceptual implications and argue that in the face of overall stability across midlife and old age, changes in the rank-ordering of people reveals a much more complex and diverse pattern of development than analyses at the trait level suggest.

Acting Like a Baby Boomer? Birth-Cohort Differences in Adults' Personality Trajectories During the Last Half a Century.

Society and developmental theory generally assume that there are wide generational differences in personality. Yet evidence showing historical change in the levels of adult Big Five traits is scarce and particularly so for developmental change. We tracked adult trajectories of personality in 4,732 participants (age: M = 52.93 years, SD = 16.69; 53% female) from the Seattle Longitudinal Study (born 1883-1976) across 50 years. Multilevel models revealed evidence for historical change in personality: At age 56, later-born cohorts exhibited lower levels of maturity-related traits (agreeableness and neuroticism) and higher levels of agency-related traits (extraversion and openness) than earlier-born cohorts. Historical changes in agreeableness and neuroticism were more pronounced among young adults, but changes in openness were less pronounced. Cohort differences in change were rare and were observed only for agreeableness; within-person increases were more pronounced among later-born cohorts. Our results yield the first evidence for historical change in the Big Five across adulthood and point to the roles of delayed social-investment and maturity effects.

Is more always better? Dose effect in a multidomain intervention in older adults at risk of dementia.

BACKGROUND: Little is known regarding the dose-response function in multidomain interventions for dementia prevention. METHOD: The Multidomain Alzheimer Preventive Trial is a 3-year randomized controlled trial comprising cognitive training, physical activity, nutrition, and omega-3 polyunsaturated fatty acids for at-risk older adults. The dose delivered (number of sessions attended) was modeled against global cognition, memory, and fluency in 749 participants. Interaction effects were assessed for age, sex, education, dementia score (CAIDE), frailty score, and apolipoprotein E (APOE) ε4 status. RESULTS: The dose-response models were non-linear functions indicating benefits up to about 12 to 14 training hours or 15 to 20 multidomain sessions followed by a plateau. Participants who benefited from a higher dose included women, younger participants, frail individuals, and those with lower education or lower risk of dementia. DISCUSSION: The non-linear function indicates that a higher dose is not necessarily better in multidomain interventions. The optimal dose was about half of the potentially available sessions.

Mortality Risk Associated With Personality Facets of the Big Five and Interpersonal Circumplex Across Three Aging Cohorts.

OBJECTIVE: To address the common reliance on the global Big Five domains in the personality and longevity literature, the present study examined mortality risk associated with subdimensions of Big Five domains as well as specific traits within the interpersonal circumplex (IPC) model of personality. METHODS: Data were drawn from three major longitudinal studies of aging that administered the NEO Personality Inventory-Revised, a comprehensive measure of the Big Five, and comprised a total of 4223 participants. Item Response Theory models were used to generate latent trait scores for each of the 30 Big Five facets and eight scales from the IPC. Pooled mortality risk estimates were obtained from demographic-adjusted Cox regression models within each study. RESULTS: With a high degree of consistency, the vulnerability facet of neuroticism was associated with higher mortality risk and the activity facet of extraversion, with lower risk. None of the openness or agreeableness facets were associated with mortality, although the IPC scales submissiveness and hostile submissiveness were linked with elevated risk. All but one of the facets in the conscientiousness domain were robustly and consistently associated with lower mortality risk. CONCLUSIONS: Findings indicate that specific facets of neuroticism and extraversion carry greater or lesser mortality risk. Broad composite scales averaging across all facets mask important personality risk factors. In contrast, nearly all facets within the conscientiousness domain confer protection against mortality. Finally, the IPC model may capture more nuanced interpersonal risk factors than the facets of Big Five agreeableness or extraversion. Understanding of the role of personality in longevity requires a more precise approach to conceptualization and measurement than broad, composite constructs usually provide.

APOEε4 Genotype and Hypertension Modify 8-year Cortical Thinning: Five Occasion Evidence from the Seattle Longitudinal Study.

We investigated individual differences in longitudinal trajectories of brain aging in cognitively normal healthy adults from the Seattle Longitudinal Study covering 8 years of longitudinal change (across 5 occasions) in cortical thickness in 249 midlife and older adults (52-95 years old). We aimed to understand true brain change; examine the influence of salient risk factors that modify an individual's rate of cortical thinning; and compare cross-sectional age-related differences in cortical thickness to longitudinal within-person cortical thinning. We used Multivariate Multilevel Modeling to simultaneously model dependencies among 5 lobar composites (Frontal, Parietal, Temporal, Occipital, and Cingulate [CING]) and account for the longitudinal nature of the data. Results indicate (1) all 5 lobar composites significantly atrophied across 8 years, showing nonlinear longitudinal rate of cortical thinning decelerated over time, (2) longitudinal thinning was significantly altered by hypertension and Apolipoprotein-E ε4 (APOEε4), varying by location: Frontal and CING thinned more rapidly in APOEε4 carriers. Notably, thinning of parietal and occipital cortex showed synergistic effect of combined risk factors, where individuals who were both APOEε4 carriers and hypertensive had significantly greater 8-year thinning than those with either risk factor alone or neither risk factor, (3) longitudinal thinning was 3 times greater than cross-sectional estimates of age-related differences in thickness in parietal and occipital cortices.

Self-perceived Difficulties in Everyday Function Precede Cognitive Decline among Older Adults in the ACTIVE Study.

OBJECTIVES: Careful characterization of how functional decline co-evolves with cognitive decline in older adults has yet to be well described. Most models of neurodegenerative disease postulate that cognitive decline predates and potentially leads to declines in everyday functional abilities; however, there is mounting evidence that subtle decline in instrumental activities of daily living (IADLs) may be detectable in older individuals who are still cognitively normal. METHODS: The present study examines how the relationship between change in cognition and change in IADLs are best characterized among older adults who participated in the ACTIVE trial. Neuropsychological and IADL data were analyzed for 2802 older adults who were cognitively normal at study baseline and followed for up to 10 years. RESULTS: Findings demonstrate that subtle, self-perceived difficulties in performing IADLs preceded and predicted subsequent declines on cognitive tests of memory, reasoning, and speed of processing. CONCLUSIONS: Findings are consistent with a growing body of literature suggesting that subjective changes in everyday abilities can be associated with more precipitous decline on objective cognitive measures and the development of mild cognitive impairment and dementia. (JINS, 2018, 24, 104-112).

The ACTIVE conceptual framework as a structural equation model.

Background/Study Context: Conceptual frameworks are analytic models at a high level of abstraction. Their operationalization can inform randomized trial design and sample size considerations. METHODS: The Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) conceptual framework was empirically tested using structural equation modeling (N=2,802). ACTIVE was guided by a conceptual framework for cognitive training in which proximal cognitive abilities (memory, inductive reasoning, speed of processing) mediate treatment-related improvement in primary outcomes (everyday problem-solving, difficulty with activities of daily living, everyday speed, driving difficulty), which in turn lead to improved secondary outcomes (health-related quality of life, health service utilization, mobility). Measurement models for each proximal, primary, and secondary outcome were developed and tested using baseline data. Each construct was then combined in one model to evaluate fit (RMSEA, CFI, normalized residuals of each indicator). To expand the conceptual model and potentially inform future trials, evidence of modification of structural model parameters was evaluated by age, years of education, sex, race, and self-rated health status. RESULTS: Preconceived measurement models for memory, reasoning, speed of processing, everyday problem-solving, instrumental activities of daily living (IADL) difficulty, everyday speed, driving difficulty, and health-related quality of life each fit well to the data (all RMSEA < .05; all CFI > .95). Fit of the full model was excellent (RMSEA = .038; CFI = .924). In contrast with previous findings from ACTIVE regarding who benefits from training, interaction testing revealed associations between proximal abilities and primary outcomes are stronger on average by nonwhite race, worse health, older age, and less education (p < .005). CONCLUSIONS: Empirical data confirm the hypothesized ACTIVE conceptual model. Findings suggest that the types of people who show intervention effects on cognitive performance potentially may be different from those with the greatest chance of transfer to real-world activities.

Does Consumer Credit Precede or Follow Health Among Older Adults? An Investigation in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) Trial.

Background and Objectives: Consumer credit has shown increasing relevance to the health of older adults; however, studies have not been able to assess the extent to which creditworthiness influences future health or health influences future creditworthiness. We assessed the relationships between 4-year pre and postmorbid consumer credit history and self-rated physical and mental health outcomes among older adults. Research Design and Methods: Generalized estimating equations models assessed pre and postmorbid credit history (credit scores, derogatory accounts, and unpaid accounts in collections) and the onset of poor self-rated health (SF-36 score <50) among 1,740 participants aged 65+ in the Advanced Cognitive Training for Independent and Vital Elderly study from 2001 to 2017, linked to TransUnion consumer credit data. Results: In any given year, up to 1/4 of participants had a major derogatory, unpaid, or collections account, and up to 13% of the sample had poor health. Each 50-point increase in credit score trended toward a 5% lower odds of poor health in the next 1 year, a 6% lower odds in the next 2 years, and a statistically significant finding of 13% lower odds by 3 years. A drop in credit score was associated with a 10% greater odds of poor health in the next year, and having a major derogatory account was associated with an 86% greater odds of poor health in the next 3 years. After poor health onset, credit scores continued to see significant losses up to the 3 years, with larger decrements over time. Discussion and Implications: Having a major derogatory account or a sudden loss in credit may be a time to monitor older adults for changes in health. After a downturn in health, supporting older adults to manage their debt may help stabilize their credit.

Alcohol effects on cognitive change in middle-aged and older adults.

OBJECTIVES: This study examines cognitive outcomes for alcohol drinking status over time, across cognitive ability and age groups. METHODS: Data (1998-2005) from n = 571 Seattle Longitudinal Study participants aged 45+years (middle-aged: 45-64, young-old: 65-75, old-old: 75+) were analyzed to examine the alcohol drinking status effect (e.g., abstinent, moderate (less than seven drinks/week), at-risk (more than eight drinks/week)) on cognitive ability (e.g., memory, reasoning, spatial, verbal number, speed abilities). RESULTS: Findings indicated that alcohol drinking status was associated with change in verbal ability, spatial ability, and perceptual speed. Decline in verbal ability was seen among alcohol abstainers and moderate alcohol consumers, but at-risk drinkers displayed relative stability. At-risk old-old adults and middle-aged adults (regardless of drinking status), displayed relative stability in spatial ability. Decline in spatial ability was however present among young-old adults across drinking status, and among abstaining and moderate drinking old-old adults. At-risk drinkers showed the most positive spatial ability trajectory. A gender effect in perceptual speed was detected, with women who abstained from drinking displaying the most decline in perceptual speed compared with women that regularly consumed alcohol, and men displaying decline in perceptual speed across drinking status. DISCUSSION: In this study, consuming alcohol is indicative of cognitive stability. This conclusion should be considered cautiously, due to study bias created from survivor effects, analyzing two time points, health/medication change status, and overrepresentation of higher socioeconomic status and white populations in this study. Future research needs to design studies that can make concrete recommendations about the relationship between drinking status and cognition.

The ACTIVE Study: Association of Race and Social Determinants of Health (SDoH) with Long-Term Outcomes and Cognitive Training Effects.

Objective: The purpose of this article is to introduce a special issue on the ACTIVE project examining the association between race and social determinants of health (SDoH) and long-term participant outcomes and training effectiveness for older Black/African Americans and Whites in the ACTIVE (for Advanced Cognitive Training for Independent and Vital Elderly) Trial on cognitive abilities, everyday functioning, and incidence of dementia. The ACTIVE study is the largest randomized clinical trial (N = 2802) of the efficacy of three types of cognitive training (memory, reasoning, speed of processing) in improving cognitive and everyday functioning in normal older adults, with follow-ups extending through 5 and 10 years post-intervention. Method: We provide background and context for studying the multiple domains of SDoH in understanding long-term participant outcomes in the ACTIVE trial and racial disparities in the efficacy of cognitive training and summarize the 11 articles in this special issue. Results: Articles in this special issue address several cross-cutting themes. These include 1) a focus on SDoH and race in relation to three cognitive abilities and driving; 2) cognitive training outcomes in older Black/African Americans (B/AA); 3) race differences in everyday function; and 4) associations of various risk factors (e.g., cardiovascular disease, obesity, depression) and protective factors (e.g., occupational complexity) for cognitive decline with health disparities in incident dementia and mortality. Conclusion: In cognitive training studies with cognitively healthy older adults, it is important to consider how factors such as race and SDoH relate to long-term participant outcomes and how they moderate intervention effects.

Disparities in First Instrumental Activity of Daily Living Difficulty between Black and White Older Adults: Findings from the Advanced Cognitive Training in Independent and Vital Elderly Study.

Objectives: Few studies have examined differences in age of onset of first self-reported instrumental activities of daily living difficulty, much less differences by race. Our objective was to determine whether there are differences in the first reported difficulty with IADLs between Black and white older adults. Methods: We analyzed data from N = 1168 participants in the Advanced Cognitive Training in Independent and Vital Elderly (ACTIVE) study. A multiple group discrete-time multiple-event process survival mixture (MEPSUM) model was used to estimate the hazard of incident IADL difficulty in seven IADL task groups. Results: No statistically significant differences were identified in the first reported IADL task group difficulty between Black and white older adults. Discussion: Our findings indicate similar patterns of early IADL difficulty in Black and white older adults, suggesting that previously reported racial disparities in ability to perform IADLs may be attributable to differences in absolute risk, not timing.

Effects of Cognitive Training on Alzheimer's Disease and Related Dementias: The Moderating Role of Social Determinants of Health.

Objective: We examined whether social determinants of health (SDoH) are associated with Alzheimer's disease and related dementias (ADRD) risk and the effects of cognitive training over a 20-year follow-up period. Methods: Data were obtained from 1605 participants in ACTIVE. SDoH measures were created using baseline data at the individual and neighborhood level. Incident ADRD was defined using administrative claims data (1999-2019). Cause-specific hazard models estimated associations between SDoH and claims-based diagnosed ADRD. Results: Higher scores on neighborhood and built environment were associated with lower ADRD risk. Trained participants obtained a greater degree of protection from ADRD when they had higher scores for SDoH domains associated with health care and education access. However, there were fewer significant SDoH moderation effects on cognitive training than expected. Discussion: Future work should continue to explore culturally tailored cognitive training interventions to reduce ADRD risk associated with SDoH that disproportionately affects racially diverse aging populations.

Does Consumer Credit Precede or Follow Changes in Cognitive Impairment Among Older Adults? An Investigation in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) Trial.

OBJECTIVES: We assessed the relationships between pre- and post-morbid consumer credit history (credit scores, debts unpaid, or in collections) and classification of mild (or greater) cognitive impairment (MCI). METHODS: Generalized Estimating Equation models assessed pre-and post-morbid credit history and MCI risk among 1740 participants aged 65+ in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, linked to TransUnion consumer credit data. RESULTS: Each 50-point increase in credit score was associated with up to 8% lower odds of MCI in the next 3 years. In contrast, new unpaid collections over doubled the odds of having MCI in the next 3 years. MCI was associated with subsequent credit score declines and a 47%-71% greater risk of having a new unpaid collection in the next 4 years. DISCUSSION: Credit declines may signal risk for future MCI. MCI may lead to financial challenges that warrant credit monitoring interventions for older adults.

Instability in longitudinal sleep duration predicts cognitive impairment in aged participants of the Seattle Longitudinal Study.

Importance: Sleep disturbances and clinical sleep disorders are associated with all-cause dementia and neurodegenerative conditions. It remains unclear how longitudinal changes in sleep impact the incidence of cognitive impairment. Objective: To evaluate how longitudinal sleep patterns contribute to age-related changes in cognitive function in healthy adults. Design Setting Participants: This study utilizes retrospective longitudinal analyses of a community-based study within Seattle, evaluating self-reported sleep (1993-2012) and cognitive performance (1997-2020) in aged adults. Main Outcomes and Measures: The main outcome is cognitive impairment as defined by sub-threshold performance on 2 of 4 neuropsychological batteries: Mini-Mental State Examination (MMSE), Mattis Dementia Rating Scale, Trail Making Test, and Wechsler Adult Intelligent Scale (Revised). Sleep duration was defined through self-report of 'average nightly sleep duration over the last week' and assessed longitudinally. Median sleep duration, change in sleep duration (slope), variability in sleep duration (standard deviation, Sleep Variability), and sleep phenotype ("Short Sleep" median ≤7hrs.; "Medium Sleep" median = 7hrs; "Long Sleep" median ≥7hrs.). Results: A total of 822 individuals (mean age of 76.2 years [11.8]; 466 women [56.7%]; 216 APOE allele positive [26.3%]) were included in the study. Analysis using a Cox Proportional Hazard Regression model (concordance 0.70) showed that increased Sleep Variability (95% CI [1.27,3.86]) was significantly associated with the incidence of cognitive impairment. Further analysis using linear regression prediction analysis (R2=0.201, F (10, 168)=6.010, p=2.67E-07) showed that high Sleep Variability (ß=0.3491; p=0.048) was a significant predictor of cognitive impairment over a 10-year period. Conclusions and Relevance: High variability in longitudinal sleep duration was significantly associated with the incidence of cognitive impairment and predictive of decline in cognitive performance ten years later. These data highlight that instability in longitudinal sleep duration may contribute to age-related cognitive decline.

Longitudinal Sleep Patterns and Cognitive Impairment in Older Adults.

Importance: Sleep disturbances and clinical sleep disorders are associated with all-cause dementia and neurodegenerative conditions, but it remains unclear how longitudinal changes in sleep impact the incidence of cognitive impairment. Objective: To evaluate the association of longitudinal sleep patterns with age-related changes in cognitive function in healthy older adults. Design, Setting, and Participants: This cross-sectional study is a retrospective longitudinal analyses of the Seattle Longitudinal Study (SLS), which evaluated self-reported sleep duration (1993-2012) and cognitive performance (1997-2020) in older adults. Participants within the SLS were enrolled as part of a community-based cohort from the Group Health Cooperative of Puget Sound and Health Maintenance Organization of Washington between 1956 and 2020. Data analysis was performed from September 2020 to May 2023. Main Outcomes and Measures: The main outcome for this study was cognitive impairment, as defined by subthreshold performance on both the Mini-Mental State Examination and the Mattis Dementia Rating Scale. Sleep duration was defined by self-report of median nightly sleep duration over the last week and was assessed longitudinally over multiple time points. Median sleep duration, sleep phenotype (short sleep, median ≤7 hours; medium sleep, median = 7 hour; long sleep, median ≥7 hours), change in sleep duration (slope), and variability in sleep duration (SD of median sleep duration, or sleep variability) were evaluated. Results: Of the participants enrolled in SLS, only 1104 participants who were administered both the Health Behavior Questionnaire and the neuropsychologic battery were included for analysis in this study. A total of 826 individuals (mean [SD] age, 76.3 [11.8] years; 468 women [56.7%]; 217 apolipoprotein E ε4 allele carriers [26.3%]) had complete demographic information and were included in the study. Analysis using a Cox proportional hazard regression model (concordance, 0.76) showed that status as a short sleeper (hazard ratio, 3.67; 95% CI, 1.59-8.50) and higher sleep variability (hazard ratio, 3.06; 95% CI, 1.14-5.49) were significantly associated with the incidence of cognitive impairment. Conclusions and Relevance: In this community-based longitudinal study of the association between sleep patterns and cognitive performance, the short sleep phenotype was significantly associated with impaired cognitive performance. Furthermore, high sleep variability in longitudinal sleep duration was significantly associated with the incidence of cognitive impairment, highlighting the possibility that instability in sleep duration over long periods of time may impact cognitive decline in older adults.

Evaluating Social Determinants of Health Domains and Their Predictive Validity Within Black/African American and White Older Adults From the ACTIVE Trial.

OBJECTIVE: To assess domains of social determinants of health (SDoH) and their associations with cognition and quality of life. METHOD: This investigation uses baseline data from individuals participating in the ACTIVE trial (n = 2505) to reproduce the SDoH domains described in Healthy People 2030 (economic stability, health care, education, neighborhood and built environment, and social and community context). Results: Results support using data from the ACTIVE trial to assess all five SDoH domains, and the ability of the composites to predict baseline performance on measures of cognition and self-reported quality of life within a sample of older adults. Additionally, higher SDoH domain scores were associated with better functioning on composite measures of cognition and higher scores for mental and general health-related quality of life with Access to Healthcare associated with all outcomes. Discussion: These findings can inform investigators interested in assessing multiple domains of SDoH and highlight the importance of access to health care within older Black/African American and White older adults.

Rural-Urban Differences in Cognition: Findings From the Advanced Cognitive Training for Independent and Vital Elderly Trial.

ObjectivesWe examined associations between three geographic areas (urban, suburban, rural) and cognition (memory, reasoning, processing speed) over a 10-year period. Methods: Data were obtained from 2539 participants in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial. Multilevel, mixed-effects linear regression was used to estimate cognitive trajectories by geographical areas over 10 years, after adjusting for social determinants of health. Results: Compared to urban and suburban participants, rural participants fared worse on all cognitive measures-memory (B = -1.17 (0.17)), reasoning (B = -1.55 (0.19)), and processing speed (B = 0.76 (0.19)) across the 10-year trajectory. Across geographic areas, greater economic stability, health care access and quality, and neighborhood resources were associated with better cognition over time. Discussion: Findings highlight the importance of geographical location when examining cognition later in life. More research examining place-based life experiences is needed to make the greatest impact on geographically diverse communities.

Long-Term Effects of Cognitive Training on All-Cause Mortality in US Older Adults.

Objectives: Cognitive abilities have been implicated as predictors of mortality in older adults. This study examines the effects of cognitive training on mortality 20 years post-intervention. Methods: Data come from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) randomized control trial (N = 2802). Participants were cognitively and physically healthy, community-dwelling adults aged 65 and older. Cox proportional hazard models were used to investigate (1) the association between baseline cognition and mortality risk and (2) the effect of ACTIVE cognitive training (memory, reasoning, and speed of processing) on mortality risk 20 years post-intervention. Results: Higher baseline cognition predicted lower mortality risk 20 years post-intervention. No significant effects of ACTIVE cognitive training in memory, reasoning, or speed of processing on mortality risk were observed. Discussion: More work is needed to identify cognitive training interventions that may lead to lower mortality risks in later adulthood.

Adult development and aging in historical context.

Human functioning and development are shaped by sociocultural contexts and by the historical changes that occur in these contexts. Over the last century, sociocultural changes such as increases in early life education have profoundly reshaped normative developmental sequences. In this article, we first briefly review how history-graded changes have influenced levels of objective performance and subjective evaluations among older adults and conclude that old age in countries such as the United States and Germany is getting younger, both on behavioral measures and in people's own perception. Second, we put these findings in a larger perspective and note some of the "presumed" causes driving historical change. Third, we identify key aspects of change that need to be further described, including history-graded change in (a) the formative role of experiences made across adulthood; (b) within-person trajectories of adult development and aging, including rates of change, patterns of variation, and causal influence; (c) the structure of very old age and the end of life; and (d) what may be expected in the forthcoming decades. We suggest a number of reasons why the rosy picture of historical change obtained for older adults over the last century may not necessarily continue in the future. In a final step, we outline promising methods that might be used to discover and test mechanisms driving history-graded changes, and to inform projection and optimization of functioning and development in future generations of older adults. (PsycInfo Database Record (c) 2020 APA, all rights reserved).