Memory and Personality Development in Adulthood: Evidence From Four Longitudinal Studies

Personality predictors of dementia diagnosis and neuropathological burden: An individual participant data meta-analysis

INTRODUCTION

The extent to which the Big Five personality traits and subjective well-being (SWB) are discriminatory predictors of clinical manifestation of dementia versus dementia-related neuropathology is unclear.

METHODS

Using data from eight independent studies (Ntotal = 44,531; Ndementia = 1703; baseline Mage = 49 to 81 years, 26 to 61% female; Mfollow-up range = 3.53 to 21.00 years), Bayesian multilevel models tested whether personality traits and SWB differentially predicted neuropsychological and neuropathological characteristics of dementia.

RESULTS

Synthesized and individual study results indicate that high neuroticism and negative affect and low conscientiousness, extraversion, and positive affect were associated with increased risk of long-term dementia diagnosis. There were no consistent associations with neuropathology.

DISCUSSION

This multistudy project provides robust, conceptually replicated and extended evidence that psychosocial factors are strong predictors of dementia diagnosis but not consistently associated with neuropathology at autopsy.

HIGHLIGHTS

N(+), C(-), E(-), PA(-), and NA(+) were associated with incident diagnosis. Results were consistent despite self-report versus clinical diagnosis of dementia. Psychological factors were not associated with neuropathology at autopsy. Individuals with higher conscientiousness and no diagnosis had less neuropathology. High C individuals may withstand neuropathology for longer before death.

Are trajectories of personality and socioeconomic factors prospectively associated with midlife cognitive function? Findings from a 12-year longitudinal study of Mexican-origin adults

Problems with memory, executive function, and language are a significant public health concern, especially when they begin during midlife. However, there is relatively little work on risk and protective factors for cognitive function in middle adulthood. Using data from 883 Mexican-origin adults assessed up to 6 times across 12 years (Mage at Time 1 = 38.2 years; range = 27-63 years), the present study examined whether developmental trajectories (levels and slopes) of Big Five personality domains and socioeconomic factors (per capita income, economic stress) were prospectively associated with cognitive function (memory, mental status, verbal fluency) at the final assessment. We found that individuals with higher levels of, and smaller decreases in, Neuroticism had worse cognitive function 12 years later. Further, individuals with higher initial Conscientiousness had better subsequent memory, mental status, and verbal fluency, and individuals with higher Openness and Extraversion had better subsequent verbal fluency (but not memory or mental status). The trajectories of per capita income and economic stress were robustly associated with cognitive function, such that higher initial levels and greater increases in socioeconomic resources had protective associations, whereas higher levels and greater increases in economic stress had deleterious associations with cognitive function. Higher education level was associated with better cognitive function 12 years later. These findings suggest that changes in personality and socioeconomic factors across adulthood are associated with cognitive function, which may be informative for interventions to support healthier cognitive aging starting at least as early as midlife. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Five-Factor Model Personality Traits and the Trajectory of Episodic Memory: Individual-Participant Meta-Analysis of 471,821 Memory Assessments from 120,640 Participants

OBJECTIVES

Five-factor model (FFM) personality traits are associated with concurrent memory function and risk of incident dementia but are less consistently associated with the change in episodic memory. The present research analyzes multiple large-scale studies with a consistent analytic approach to evaluate the association between personality and change in episodic memory over time.

METHOD

Across nine public longitudinal data sets, 120,640 participants provided 471,821 memory assessments over up to 26 years (age range 18-108). FFM traits were tested as predictors of the average level (intercept) and change over time (slope) of episodic memory. Results from the individual samples were meta-analyzed to summarize the associations.

RESULTS

Consistent with expectations for the intercept, higher neuroticism was associated with worse memory performance, whereas higher openness and conscientiousness were associated with better performance; extraversion and agreeableness were also associated with better performance. Higher neuroticism and lower conscientiousness were related to declines in memory only in samples with more than two assessments of memory. The other three traits were unrelated to memory slope. The pattern was similar when participants with dementia were excluded from the analysis, and the association with the slope was not moderated by age.

DISCUSSION

FFM traits have a robust association with average memory performance. Higher neuroticism and lower conscientiousness were associated with declines in memory performance only among samples with more than two memory assessments. The heterogeneity across studies suggests that multiple memory assessments are needed to reliably detect change over time, which may be one reason for past inconsistencies across studies.

IQ in Adolescence and Cognition over 50 years later: The Mediating Role of Adult Personality

There is substantial evidence for the association between higher early life IQ and better cognition in late life. To advance knowledge on potential pathways, the present study tested whether Five-Factor Model personality traits in adulthood mediate the association between adolescent IQ and later-life cognition. Participants were from the Graduate sample of the Wisconsin Longitudinal Study on Aging (WLS; N= 3,585). IQ was assessed in 1957 (about age 17), personality was assessed in 2003-2005 (age = 64), and cognition was assessed in 2011 (age = 71). Controlling for demographic factors, higher IQ in adolescence was related to higher openness, lower neuroticism, lower extraversion, lower agreeableness and lower conscientiousness in adulthood. Higher openness partially mediated the association between higher IQ and better cognition. Additional analyses indicated that the pattern of associations between IQ, personality and cognition was similar when the polygenic score for cognition was included as an additional covariate. Although effect size were small, this study provides new evidence that openness in adulthood is on the pathway between early life IQ and later-life cognition.

Personality Change Profiles and Changes in Cognition Among Middle-Aged and Older Adults

Research on the relationship between personality traits and cognitive abilities has primarily used cross-sectional designs and considered personality traits individually in relation to cognitive dimensions. This study (N = 2,652) examined the relationship between Big Five personality change profiles and change in cognitive factors, episodic memory and executive functioning. Latent profile analysis was used to capture patterns of change across the Big Five traits. Three profiles of personality change were defined: Decreasers, Maintainers, and Increasers. The Decreasers declined more in episodic memory compared to the Increasers and Maintainers. Also, the Decreasers declined more in executive functioning compared to the Increasers, but not the Maintainers. The findings advance our understanding of the links between patterns of personality change and cognitive aging.