The association between facets of conscientiousness and performance-based and informant-rated cognition, affect, and activities in older adults

Personality nuances and risk of dementia: Evidence from two longitudinal studies

Personality traits are broad constructs composed of nuances, operationalized by personality items, that can provide a more granular understanding of personality associations with health outcomes. This study examined the associations between personality nuances and incident dementia and evaluated whether nuances associations replicate across two samples. Health and Retirement Study (HRS, N = 11,400) participants were assessed in 2006/2008, and the English Longitudinal Study of Ageing (ELSA, N = 7453) participants were assessed in 2010/2011 on personality and covariates. Dementia incidence was tracked for 14 years in the HRS and 8 years in ELSA. In both HRS and ELSA, higher neuroticism domain and nuances (particularly nervous and worry) were related to a higher risk of incident dementia, whereas higher conscientiousness domain and nuances (particularly responsibility and organization) were associated with a lower risk of dementia. To a lesser extent, higher extraversion (active), openness (broad-minded, curious, and imaginative), and agreeableness (helpful, warm, caring, and sympathetic) nuances were associated with a lower risk of dementia, with replicable effects across the two samples. A poly-nuance score, aggregating the effects of personality items, was associated with an increased risk of incident dementia in the HRS and ELSA, with effect sizes slightly stronger than those of the personality domains. Clinical, behavioral, psychological, and genetic covariates partially accounted for these associations. The present study provides novel and replicable evidence for specific personality characteristics associated with the risk of incident dementia.

Personality and cognitive errors in the Healthy Aging in Neighborhoods of Diversity across the Life Span study

This study examines the association between personality and cognitive errors in the Healthy Aging in Neighborhoods of Diversity across the Life Span study, a sample diverse across race (Black, White) and SES (above, below 125% of the federal poverty line). Participants (N=1,062) completed a comprehensive personality questionnaire and were administered a brief mental status screener of cognitive errors. Higher neuroticism was associated with more cognitive errors, whereas higher openness and conscientiousness were associated with fewer errors. These associations were independent of age, sex, race, poverty status, and education and were generally not moderated by these factors. These findings support the associations between personality and cognition across race and SES.

Purpose in life and cognitive performance and informant ratings of cognitive decline, affect, and activities

OBJECTIVE

To examine (1) the association between purpose in life and multiple domains of cognitive function and informant-rated cognitive decline, affect, and activities; (2) whether these associations are moderated by sociodemographic factors, cognitive impairment, or depression; (3) whether the associations are independent of other aspects of well-being and depressive symptoms.

METHOD

As part of the 2016 Harmonized Cognitive Assessment Protocol from the Health and Retirement Study, participants completed a battery of cognitive tests and nominated a knowledgeable informant to rate their cognitive decline, affect, and activities. Participants with information available on their purpose in life from the 2014/2016 Leave Behind Questionnaire were included in the analytic sample (N = 2,812).

RESULTS

Purpose in life was associated with better performance in every cognitive domain examined (episodic memory, speed-attention, visuospatial skills, language, numeric reasoning; median β =.10, p <.001; median d =.53). Purpose was likewise associated with informant-rated cognitive decline and informant-rated affective and activity profiles beneficial for cognitive health (median β =.18, p < .001; median d =.55). There was little evidence of moderation by sociodemographic or other factors (e.g., depression). Life satisfaction, optimism, positive affect, and mastery were generally associated with cognition. When tested simultaneously with each other and depressive symptoms, most dimensions were reduced to non-significance; purpose remained a significant predictor.

CONCLUSIONS

Purpose in life is associated with better performance across numerous domains of cognition and with emotional and behavioral patterns beneficial for cognitive health that are observable by knowledgeable others. These associations largely generalize across demographic and clinical groups and are independent of other aspects of well-being.

Physical, cognitive, and social activities as mediators between personality and cognition: evidence from four prospective samples

OBJECTIVES

The present study examined how activity engagement mediates the association between personality and cognition.

METHODS

Participants were middle-aged and older adults (Age range: 24-93 years; N > 16,000) from the Midlife in the United States Study, the Health and Retirement Study, the English Longitudinal Study of Ageing, and the Wisconsin Longitudinal Study of Aging. In each sample, personality traits and demographic factors were assessed at baseline, engagement in cognitive, physical, and social activities was assessed in a second wave, and cognition was measured in a third wave, 8 to 20 years later.

RESULTS

Random-effect meta-analyses indicated that lower neuroticism and higher extraversion, openness, and conscientiousness were prospectively associated with better cognition. Most of these associations were partly mediated by greater engagement in physical and cognitive activities but not social activities. Physical activity accounted for 7% (neuroticism) to 50% (extraversion) and cognitive activity accounted for 14% (neuroticism) to 45% (extraversion) of the association with cognition.

CONCLUSION

The present study provides replicable evidence that physical and cognitive activities partly mediate the prospective association between personality traits and cognitive functioning.

Personality and Cognition: The Mediating Role of Inflammatory Markers

OBJECTIVES

Five-Factor Model personality traits are associated consistently with cognition. Inflammation has been hypothesized as a biological pathway in this association, but this assumption has yet to be tested. The present study tested inflammatory markers as mediators between personality traits and cognition.

METHODS

Participants were from the Health and Retirement Study (HRS; N = 4,364; 60% women; mean age = 64.48 years, standard deviation = 8.79). Personality traits and demographic factors were assessed in 2010/2012. Data on inflammatory markers (high-sensitivity C-reactive protein [hsCRP], interleukin-6 [IL-6], soluble tumor necrosis factor 1 (sTNFR1), interleukin-10 [IL-10], interleukin-1 receptor antagonist [IL-1Ra], and transforming growth factor [TGF]-β1) were obtained in 2016 from the HRS Venuous Blood Study. Cognition was assessed in 2020 using the modified Telephone Interview for Cognitive Status.

RESULTS

Higher neuroticism was related to lower cognition at follow-up, whereas higher extraversion, openness, agreeableness, and conscientiousness were associated with better cognition. Higher extraversion and higher conscientiousness were related to lower hsCRP, IL-6, IL-10, IL-1Ra, and sTNFR1, and higher openness was associated with lower IL-10, IL-1Ra, and sTNFR1 and to higher soluble TGF-β1. Lower sTNFR1 partially mediated the associations between conscientiousness, extraversion, and openness and cognition at follow-up, explaining an estimated 4%-12% of these associations. The mediating role of sTNFR1 persisted when physical activity and depressive symptoms were included as additional mediators.

DISCUSSION

The present study provides new evidence on personality and inflammatory markers. Consistent with the inflammation hypothesis, the sTNFR1 finding supports a potential biological pathway between personality and cognition.

Association of personality facets and cognition in the Lifelines population-based cohort study

BACKGROUND

Personality traits have been associated with cognitive functioning and risk of cognitive decline. Fewer studies have investigated how personality facets are associated with cognition in large cohorts with a prospective design.

METHODS

The association between eight personality facets and cognition (speed measures reflecting psychomotor speed and visual attention; hit rate measures reflecting visual learning and working memory) was analyzed in middle-aged adults from the Lifelines cohort (N = 79911; age 43 ± 11 years).

RESULTS

High hostility, high vulnerability, low excitement seeking, and low competence were associated with worse cognitive performance on all tasks. Impulsivity-related facets had weak and differential associations, with self-discipline negatively associated with accuracy and deliberation negatively associated with speed. These associations remained largely unchanged when accounting for lifestyle factors (smoking, alcohol consumption, physical activity). The associations with cognition were stronger in older people for impulsiveness, deliberation, and hostility, while stronger in younger people for excitement seeking, self-discipline, and vulnerability.

CONCLUSION

In a large population-based sample with a broad age range, the associations of personality facets with cognitive functioning had small effect sizes, were independent of lifestyle factors, and varied with age and among facets within the same personality domain. These findings highlight the importance of developmental stages and facet-level research in personality-cognition associations.

The Big Five as Predictors of Cognitive Function in Individuals with Bipolar Disorder

The connection between cognitive function and the "Big Five" personality traits (openness, conscientiousness, extraversion, agreeableness, and neuroticism) in the general population is well known; however, studies researching bipolar disorder (BD) are scarce. Therefore, this study aimed to investigate the Big Five as predictors of executive function, verbal memory, attention, and processing speed in euthymic individuals with BD (cross-sectional: n = 129, including time point t1; longitudinal: n = 35, including t1 and t2). Participants completed the NEO Five-Factor Inventory, the Color and Word Interference Test, the Trail Making Test, the d2 Test of Attention Revised, and the California Verbal Learning Test. The results showed a significant negative correlation between executive function and neuroticism at t1. Changes in cognitive function between t1 and t2 did not correlate with and could not be predicted by the Big Five at t1. Additionally, worse executive function at t2 was predicted by higher neuroticism and lower conscientiousness at t1, and high neuroticism was a predictor of worse verbal memory at t2. The Big Five might not strongly impact cognitive function over short periods; however, they are significant predictors of cognitive function. Future studies should include a higher number of participants and more time in between points of measurement.

Five-Factor Model Personality Domains and Facets Associated with Markers of Cognitive Health

Using a diverse, age-stratified sample (N=3,478; age range 18-90) this study examines the cross-sectional association between five-factor model personality traits - domains and facets - and three measures of cognitive health - processing speed, visuospatial ability, subjective memory - and whether these associations vary by age, race, and ethnicity. Consistent with the literature on personality and cognitive health, higher openness and conscientiousness were associated with better cognitive performance and subjective memory, whereas higher neuroticism was associated with slower processing speed and worse subjective memory but was unrelated to visuospatial ability. Moderation analyses suggested some associations were stronger in midlife compared to younger and older adulthood but were generally similar across race and ethnicity. The facet-level analyses indicated the components of each domain most strongly associated with cognitive function (e.g., the responsibility facet of conscientiousness) and suggested some differences across facets within the same domain (e.g., depression was associated with worse performance, whereas anxiety was unrelated to performance; sociability was the only facet of extraversion associated with worse performance). The present research is consistent with the larger literature on personality and cognition and extends it by documenting similarities and differences across facets and demographic groups.

Measures of physical performance as mediators between personality and cognition in two prospective studies

Few studies have examined the pathways linking personality to cognition. This study aimed to examine whether measures of physical performance (gait speed, peak expiratory flow (PEF), and grip strength) mediated the association between five-factor model personality traits and cognition (memory performance, subjective memory, and informant-rated cognition). Participants were aged 57 to 95 years from the Health and Retirement Study (HRS, N = 4,109) and the English Longitudinal Study of ageing (ELSA, N = 3,584). In HRS, personality and demographic factors were assessed in 2008/2010, physical performance in 2012/2014, and memory performance and subjective memory in 2016/2018. Informant-rated cognition was obtained in 2016 for an HRS subsample. In ELSA, personality and demographic factors were assessed in 2010/2011, physical performance in 2012/2013, and objective and subjective memory in 2014/2015. Informant-rated cognition was obtained in 2018 for an ELSA subsample. With a few exceptions, replicable patterns of mediation were found across HRS and ELSA. Slower gait speed partially mediated the association between higher neuroticism, lower conscientiousness and worse scores on all three cognitive measures (memory performance, subjective memory, and informant-rated cognition). Slower gait also partially mediated the association between openness and both objective and subjective memory. There was less replicable evidence for a mediating role of PEF and grip strength. The present study advances knowledge on the pathways linking personality to cognition in older adults and supports the hypothesis that personality associations with better physical function can help support healthy cognitive aging.

Personality traits and perceived cognitive function in lebanese healthcare professionals

BACKGROUND

The healthcare field, a well-known field associated with variety of stressors, leaves healthcare professionals at an increased risk of both physical and mental problems. COVID-19 pandemic has recently been added to the stressful factors by endangering further the cognitive function of healthcare workers. On another hand, personality traits have been shown to have pervasive associations with functioning across various cognitive domains. Thus, this study aims to evaluate association between personality traits and perceived cognitive function among healthcare professionals in Lebanon during the collapsing period (following the severe economic crisis and the COVID-19 pandemic).

METHODS

This cross-sectional study was conducted between November 2021 and January 2022 enrolled 406 Lebanese participants using the convenience sampling technique for data collection. Healthcare professionals from all specialties who received the online link to the survey were eligible to participate. The Big Five Inventory-2 (BFI-2) and Fact Cog scale were used to assess personality traits and cognitive function.

RESULTS

After adjustment over all variables (age, gender, household crowding index, physical activity index, marital status, profession and the other four personality traits), higher negative emotionality was significantly associated with a worse cognitive function, whereas more extroversion and conscientiousness were significantly associated with a better cognitive function.

CONCLUSION

Our study adds to the narrow body of research revolving around the relationship between personality traits and perceived cognitive function in Lebanese healthcare professionals during these hard times in Lebanon. These results show that the choice of these cognitive processes is strongly affected by different personality traits, such as extroversion, conscientiousness, and negative emotionality. This study encourages the need to conduct further research that assess the changes in cognition in life stressors along with personality traits.

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.

The mediating role of Vitamin D in the association between personality and memory: Evidence from two samples

Five-Factor Model (FFM) personality traits are consistently related to cognition in old age. However, little is known about the biological mediators of this association. The present study examined whether levels of Vitamin D mediated the association between personality and memory. Participants were adults aged 50-96 years from the Health and Retirement Study (HRS, N = 5229) and the English Longitudinal Study of Ageing (ELSA, N = 4249). In HRS, personality and demographic factors were assessed in 2012/2014, Vitamin D was assessed in 2016, and memory was assessed in 2018. In ELSA, personality and demographic factors were obtained in 2010/2011, Vitamin D was measured in 2012/2013, and memory was assessed in 2014/2015. In both samples, higher extraversion and conscientiousness were related to higher levels of Vitamin D, whereas higher neuroticism was related to lower Vitamin D. In both samples, higher Vitamin D partly mediated the association between both higher extraversion and conscientiousness and better memory. The association between higher neuroticism and worse memory at follow-up was partially mediated by lower Vitamin D in the HRS and ELSA. Vitamin D did not mediate the association between higher openness and better memory. The present study extends the personality-cognition literature by providing new replicable evidence that Vitamin D is a biological mediator.

The relationship between temperament, polygenic score for intelligence and cognition: A population-based study of middle-aged adults

We investigated whether temperament modifies an association between polygenic intelligence potential and cognitive test performance in midlife. The participants (n = 1647, born between 1962 and 1977) were derived from the Young Finns Study. Temperament was assessed with Temperament and Character Inventory over a 15-year follow-up (1997, 2001, 2007, 2012). Polygenic intelligence potential was assessed with a polygenic score for intelligence. Cognitive performance (visual memory, reaction time, sustained attention, spatial working memory) was assessed with CANTAB in midlife. The PGSI was significantly associated with the overall cognitive performance and performance in visual memory, sustained attention and working memory tests but not reaction time test. Temperament did not correlate with polygenic score for intelligence and did not modify an association between the polygenic score and cognitive performance, either. High persistence was associated with higher visual memory (B = 0.092; FDR-adj. p = 0.007) and low harm avoidance with higher overall cognitive performance, specifically better reaction time (B = -0.102; FDR-adj; p = 0.007). The subscales of harm avoidance had different associations with cognitive performance: higher "anticipatory worry," higher "fatigability," and lower "shyness with strangers" were associated with lower cognitive performance, while the role of "fear of uncertainty" was subtest-related. In conclusion, temperament does not help or hinder one from realizing their genetic potential for intelligence. The overall modest relationships between temperament and cognitive performance advise caution if utilizing temperament-related information e.g. in working-life recruitments. Cognitive abilities may be influenced by temperament variables, such as the drive for achievement and anxiety about test performance, but they involve distinct systems of learning and memory.