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 ß =.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 ß =.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.

Purpose in life and cognitive health: a 28-year prospective study.

OBJECTIVES: To examine the prospective association between purpose in life measured at three points across middle and older adulthood and cognitive outcomes assessed 8-28 years later. DESIGN: Prospective Study. SETTING: Wisconsin Longitudinal Study of Aging (WLS). PARTICIPANTS: WLS participants who reported on their purpose in life at Round 4 (1992-1994; Mage = 52.58), Round 5 (2003-2007; Mage = 63.74), and/or Round 6 (2010-2012; Mage = 70.25) and were administered a cognitive battery at Round 7 (2020; Mage = 79.94) were included in the analysis (N = 4,632). MEASUREMENTS: Participants completed the Ryff measure of purpose in life and were administered the telephone interview for cognitive status and measures of verbal fluency, digit ordering, and numeric reasoning. RESULTS: Purpose in life measured at age 52 was related to better global cognitive function and verbal fluency but unrelated to dementia at age 80. In contrast, purpose in life at ages 63-70 was associated with lower likelihood of dementia, as well as better global cognitive function and verbal fluency at age 80. The effect sizes were modest (median Beta coefficient = .05; median odds ratio = .85). A slightly steeper decline in purpose in life between ages 52 and 70 was found for individuals with dementia at age 80. CONCLUSIONS: Purpose in life is associated with healthier cognitive function measured up to 28 years later. Individuals with lower purpose, especially in their 60s or older, and with steeper declines in purpose, are more likely to have dementia at age 80.

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.

Prevalence and factors associated with probable depression among the oldest old during the Covid-19 pandemic: evidence from the large, nationally representative 'Old Age in Germany (D80+)' study.

BACKGROUND: To date, most studies examining the prevalence and determinants of depression among individuals aged 80 and over have used geographically limited samples that are not generalisable to the wider population. Thus, our aim was to identify the prevalence and the factors associated with probable depression among the oldest old in Germany based on nationally representative data. METHODS: Data were taken from the nationally representative 'Old Age in Germany (D80+)' study (n = 8386; November 2020 to April 2021) covering both community-dwelling and institutionalised individuals aged 80 and over. The Short Form of the Depression in Old Age Scale was used to quantify probable depression. RESULTS: Probable depression was found in 40.7% (95% CI: 39.5% to 42.0%) of the sample; 31.3% were men (95% CI: 29.7% to 32.9%) and 46.6% women (95% CI: 44.9% to 48.3%). The odds of probable depression were positively associated with being female (odds ratio (OR): 1.55, 95% CI: 1.30 to 1.84), being divorced (compared to being married, OR: 1.33, 95% CI: 1.01 to 1.76), being widowed (OR: 1.14, 95% CI: 1.00 to 1.30), having a low education (e.g., medium education compared to low education, OR: 0.86, 95% CI: 0.74 to 0.99), living in an institutionalised setting (OR: 2.36, 95% CI: 1.84 to 3.02), living in East Germany (OR: 1.21, 95% CI, 1.05 to 1.39), not having German citizenship (German citizenship compared to other citizenship, OR: 0.55, 95% CI: 0.31 to 0.95), poor self-rated health (OR: 0.31, 95% CI: 0.28 to 0.34), and the number of chronic conditions (OR: 1.12, 95% CI: 1.09 to 1.14). CONCLUSION: About four out of 10 individuals aged 80 and over in Germany had probable depression, underlining the importance of this challenge. Knowledge of specific risk factors for this age group may assist in addressing older adults at risk of probable depression.

The Association between Happiness and Cognitive Function in the UK Biobank.

Feelings of happiness have been associated with better performance in creative and flexible thinking and processing. Less is known about whether happier individuals have better performance on basic cognitive functions and slower rate of cognitive decline. In a large sample from the UK Biobank (N=17,885; Age 40-70 years), we examine the association between baseline happiness and cognitive function (speed of processing, visuospatial memory, reasoning) over four assessment waves spanning up to 10 years of follow-up. Greater happiness was associated with better speed and visuospatial memory performance across assessments independent of vascular or depression risk factors. Happiness was associated with worse reasoning. No association was found between happiness and the rate of change over time on any of the cognitive tasks. The cognitive benefits of happiness may extend to cognitive functions such as speed and memory but not more complex processes such as reasoning, and happiness may not be predictive of the rate of cognitive decline over time. More evidence on the association between psychological well-being and different cognitive functions is needed to shed light on potential interventional efforts.

Personality and Risk of Incident Stroke in 6 Prospective Studies.

BACKGROUND: A large literature has examined a broad range of factors associated with increased risk of stroke. Few studies, however, have examined the association between personality and stroke. The present study adopted a systematic approach using a multi-cohort design to examine the associations between 5-Factor Model personality traits (neuroticism, extraversion, openness, agreeableness, and conscientiousness) and incident stroke using data from 6 large longitudinal samples of adults. METHODS: Participants (age range: 16-104 years old, N=58 105) were from the MIDUS (Midlife in the United States) Study, the HRS (Health and Retirement Study), The US (Understanding Society) study, the WLS (Wisconsin Longitudinal Study), the NHATS (National Health and Aging Trends Study), and the LISS (Longitudinal Internet Studies for the Social Sciences). Personality traits, demographic factors, clinical and behavioral risk factors were assessed at baseline; stroke incidence was tracked over 7 to 20 years follow-up. RESULTS: Meta-analyses indicated that higher neuroticism was related to a higher risk of incident stroke (hazard ratio, 1.15 [95% CI, 1.10-1.20]; P<0.001), whereas higher conscientiousness was protective (HR, 0.89 [95% CI, 0.85-0.93]; P<0.001). Additional meta-analyses indicated that BMI, diabetes, blood pressure, physical inactivity, and smoking as additional covariates partially accounted for these associations. Extraversion, openness, and agreeableness were unrelated to stroke incidence. CONCLUSIONS: Similar to other cardiovascular and neurological conditions, higher neuroticism is a risk factor for stroke incidence, whereas higher conscientiousness is a protective factor.

Physical activity and cognitive function: moment-to-moment and day-to-day associations.

BACKGROUND: The beneficial effect of acute physical exercise on cognitive performance has been studied in laboratory settings and in long-term longitudinal studies. Less is known about these associations in everyday environment and on a momentary timeframe. This study investigated momentary and daily associations between physical activity and cognitive functioning in the context of everyday life. METHODS: Middle-aged adults (n = 291, aged 40-70) were asked to wear accelerometers and complete ecological momentary assessments for eight consecutive days. Processing speed and visual memory were assessed three times per day and self-rated evaluations of daily cognition (memory, thinking, and sharpness of mind) were collected each night. The number of minutes spent above the active threshold (active time) and the maximum vector magnitude counts (the highest intensity obtained) before each cognitive test and at a daily level were used as predictors of momentary cognitive performance and nightly subjective cognition. Analyses were done with multilevel linear models. The models were adjusted for temporal and contextual factors, age, sex, education, and race/ethnicity. RESULTS: When participants had a more active time or higher intensity than their average level within the 20 or 60 minutes prior to the cognitive test, they performed better on the processing speed task. On days when participants had more active time than their average day, they rated their memory in the evening better. Physical activity was not associated with visual memory or self-rated thinking and sharpness of mind. CONCLUSIONS: This study provides novel evidence that outside of laboratory settings, even small increases in physical activity boost daily processing speed abilities and self-rated memory. The finding of temporary beneficial effects is consistent with long-term longitudinal research on the cognitive benefits of physical activity.

Loneliness and risk of all-cause, Alzheimer's, vascular, and frontotemporal dementia: a prospective study of 492,322 individuals over 15 years.

OBJECTIVES: This study examined the association between loneliness and risk of incident all-cause dementia and whether the association extends to specific causes of dementia. DESIGN: Longitudinal. SETTING: Community. PARTICIPANTS: Participants were from the UK Biobank (N = 492,322). INTERVENTION: None. MEASUREMENTS: Loneliness was measured with a standard item. The diagnosis of dementia was derived from health and death records, which included all-cause dementia and the specific diagnoses of Alzheimer's disease (AD), vascular dementia (VD), and frontotemporal dementia (FTD), over 15 years of follow-up. RESULTS: Feeling lonely was associated with a nearly 60% increased risk of all-cause dementia (HR = 1.59, 95% CI = 1.51-1.65; n = 7,475 incident all-cause). In cause-specific analyses, loneliness was a stronger predictor of VD (HR = 1.82, 95% CI = 1.62-2.03; n = 1,691 incident VD) than AD (HR = 1.40, 95% CI = 1.28-1.53; n = 3135 incident AD) and was, surprisingly, a strong predictor of FTD (HR = 1.64, 95% CI = 1.22-2.20; n = 252 incident FTD). The associations were robust to sensitivity analyses and were attenuated but remained significant accounting for clinical (e.g. diabetes) and behavioral (e.g. physical activity) risk factors, depression, social isolation, and genetic risk. The association between loneliness and all-cause and AD risk was moderated by APOE ϵ4 risk status such that the increased risk was apparent in both groups but stronger among non-carriers than carriers of the risk allele. CONCLUSION: Loneliness is associated with increased risk of multiple types of dementia.

Sense of Purpose in Life and Subjective Cognitive Failures.

A greater sense of purpose in life is an aspect of well-being associated with markers of cognitive health across adulthood, including subjective cognition. The current research extends this work to examine how purpose is associated with cognitive failures, which are momentary lapses in cognitive function, whether this association varies by age, sex, race, or education, and whether it is accounted for by depressed affect. Adults across the United States (N=5,100) reported on their sense of purpose in life, recent cognitive failures in four domains (memory, distractibility, blunders, names), and depressed affect. Purpose was associated with fewer cognitive failures overall and within each domain (median d=.30, p<.01), controlling for sociodemographic covariates. These associations were similar across sex, education, and racial groups but were stronger at relatively older than younger ages. Depressed affect accounted for all the association between purpose and cognitive failures among adults younger than 50; the association was reduced by half but remained significant among participants 50 and older. Purpose was associated with fewer cognitive failures, especially in the second half of adulthood. Purpose may be a psychological resource that helps support subjective cognition among relatively older adults, even after accounting for depressed affect.

Purpose in life, stress mindset, and perceived stress: Test of a mediational model.

Purpose in life is associated with less perceived stress and more positive worldviews. This study examined whether people with more purpose adopt a mindset that views stress as beneficial rather than harmful and whether this mindset is one mechanism between purpose and less stress. We used a short-term longitudinal study (N=2,147) to test stress mindset as a mediator between purpose in life measured prior to the pandemic and stress measured early in the pandemic. We also tested Covid-related worry as a mechanism, given the measurement period spanned pre-pandemic to the first shutdowns in the United States. In contrast to expectations, purpose was unrelated to whether stress was conceptualized as beneficial or harmful (b=.00, SE=.02; p=.710) and thus stress mindset did not mediate the prospective association between purpose and stress. Both purpose in life (b=-.41, SE=.04, p<.001) and stress mindset (b=-.24, SE=.04; p<.001) were independent prospective predictors of stress. Purpose was related to less Covid-related worry, which was a significant mechanism between purpose and stress (indirect effect=-.03, SE=.01; p=.023). A stress-is-enhancing mindset predicted less stress but did not explain why purpose was associated with less perceived stress, whereas fewer Covid-related worries was one pathway from purpose to less stress.

Multidimensional Assessment of Subjective Well-Being and Risk of Dementia: Findings from the UK Biobank Study.

This study aimed to examine the associations between subjective well-being (SWB) and risk of all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VD). We adopted a multidimensional approach to SWB that included the level and breadth of SWB, the latter indicating the extent to which SWB spreads across life domains. Participants (N=171,197; mean age=56.78; SD=8.16 years) were part of the UK Biobank and were followed up to 8.78 years. Domain-general and domain-specific SWB were measured by single items, and the breadth of SWB was indexed with a cumulative score of satisfaction across domains. Dementia incidence was ascertained through hospital and death records. Cox regression was used to examine the association between SWB indicators and risk of all-cause dementia, AD, and VD. General happiness, health and family satisfaction, and satisfaction breadth (satisfaction in multiple domains) were associated with lower risk of all-cause dementia. The associations held after accounting for socio-demographics, health, behavioral, and economic covariates, and depressive symptoms. Health satisfaction and the breadth of satisfaction were also associated with lower risk of AD and VD, with a pattern of slightly stronger associations for VD compared to AD. Some life domains (e.g., health) may be more fruitfully targeted to promote well-being and help protect against dementia, but it is also important to enhance well-being across multiple domains to maximize the protective effects.

Sense of Purpose in Life and Markers of Hearing Function: Replicated Associations across Two Longitudinal Cohorts.

INTRODUCTION: A sense of purpose in life is a psychological resource that is associated with healthier outcomes. The present research examines whether a greater sense of purpose in life is associated with subjective and objective markers of hearing health and whether hearing acuity contributes to the association between purpose and episodic memory. We sought to evaluate whether these associations were replicable across 2 independent samples. METHODS: Participants in the Health and Retirement Study (N = 14,291) and the English Longitudinal Study of Ageing (N = 8,844) reported on their purpose in life and perceived hearing quality at baseline. Hearing acuity was measured using an audiometer 2-4 years later, and episodic memory was measured at baseline and 6-8 years later. RESULTS: In both samples, higher purpose in life was associated with better hearing quality measured concurrently, lower risk of either subjective or objective hearing impairment, and hearing acuity accounted for some of the longitudinal relation between sense of purpose and better episodic memory. DISCUSSION: Across samples, measures, and analytical approaches, the present research indicates replicable associations between sense of purpose in life and hearing health. It further indicates that hearing may be one factor that associates purpose with better episodic memory.

The association between purpose/meaning in life and verbal fluency and episodic memory: a meta-analysis of >140,000 participants from up to 32 countries.

OBJECTIVES: Feelings of purpose and meaning in life are protective against consequential cognitive outcomes, including reduced risk of Alzheimer's disease and dementia. Purpose and meaning are likely to also be associated with cognitive functions on the pathway to dementia. The objective of the current research was to test whether both purpose in life and meaning in life are associated with higher verbal fluency and better episodic memory and whether these associations varied by sociodemographic characteristics or economic characteristics of the country. DESIGN: Prospective meta-analysis of cross-sectional associations based on individual participant data. SETTING: Established cohort studies with measures of either purpose in life or meaning in life and verbal fluency and episodic memory. PARTICIPANTS: Across the cohorts, there were over 140,000 participants from 32 countries from North and South America, Europe, and the Middle East. RESULTS: The meta-analysis indicated that purpose and meaning were associated with better performance on both the verbal fluency (meta-analytic partial r = .098, 95% confidence interval [CI] = .080, .116, p < .001) and episodic memory (r = .117, 95% CI = .100, .135, p < .001) task and that these associations were similar across measures of purpose in life and meaning in life. There was modest evidence that these associations were slightly stronger in relatively lower-income countries, and there was less consistent evidence that they varied by age, gender, or education. DISCUSSION: These findings indicate a robust association between purpose/meaning and both verbal fluency and episodic memory across demographic groups and cultural context. Purpose/meaning may be a useful target of intervention for healthier cognitive aging.

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.

Self-reported sense of purpose in life and proxy-reported behavioral and psychological symptoms of dementia in the last year of life.

Objectives:Behavioral and psychological symptoms of dementia (BPSD) are among the most challenging aspects of dementia for individuals living with dementia and their caregivers. Identifying factors associated with resilience to BPSD may inform interventions to reduce them. The present research examines whether purpose in life is associated with BPSD in the last year of life.Method:Participants from the Health and Retirement Study were selected if they reported on their sense of purpose, had evidence of a memory impairment, died across the follow-up, and a proxy completed the End of Life survey that included BPSD (N = 2473). Self-reported sense of purpose was tested as a predictor of the sum of symptoms and each indivdual symptom in the last year of life.Results:Purpose in life was associated with fewer BPSD overall. Of the individual symptoms, purpose was associated with less risk of psychological symptoms, specfiically less depression, periodic confusion, uncontrolled temper, but not with motor or perceptual symptoms.Conclusion: These results are consistent with growing evidence that purpose is associated with better cognitive outcomes. Purpose may be a useful target of intervention to improve outcomes across the spectrum of dementia.

Personality and change in perceived control during the acute stage of the coronavirus pandemic.

Lower perceived control (PC) is related to maladaptive psychological responses to stressful events, yet it is unclear whether longer-term situations are associated with PC change over time. This study examined PC change during the beginning of the coronavirus pandemic and whether trajectories varied by age and personality. Personality was assessed in 2455 U.S. adults (18-100 years) from an online study conducted January-February 2020. PC was assessed across three follow-ups (March-July 2020). Latent growth curves modeled PC change. In controlled models, PC decreased (ß = -0.107, p = .005). Older adults had higher PC than younger adults (ß = 0.012, p = .001), and experienced less PC decline (ß = 0.012, p < .001). All personality traits but Openness were related to PC at baseline (ßs ranged from -0.912 to 0.543, ps < .001). Conscientiousness (ß = 0.155, p = .002), Extraversion (ß = 0.128, p = .008), and Agreeableness (ß = 0.099, p = .044) were associated with less PC decline. Employment (ß = 0.160, p = .022), health (ß = 0.133, p = .002), and disease burden (ß = -0.056, p = .014) were also associated with PC change. These results were largely driven by the financial dimension of PC. This study provides evidence for PC change during the COVID-19 pandemic and identifies sociodemographic, personality, and health moderators of PC trajectory.

Personality and Headaches: Findings From Six Prospective Studies.

OBJECTIVE: The present study examined the association between personality traits and concurrent and incident headaches. METHODS: Participants (n = 34,989), aged 16 to 107 years were from the Midlife in the United States study, the Midlife in Japan study, the Health and Retirement Study, the Wisconsin Longitudinal Study Graduate and Siblings samples, and the Longitudinal Internet Studies for the Social Sciences. Demographic factors, personality traits, and headaches were assessed at baseline. Headaches were assessed again 4 to almost 20 years later. RESULTS: Across the samples, higher neuroticism was related to a higher likelihood of concurrent (combined odd ratio = 1.41, 95% confidence interval [CI] = 1.28-1.55, p < .001) and incident (combined odd ratio = 1.28, 95% CI = 1.12-1.46, p < .001) headaches, whereas higher extraversion was associated with a lower likelihood of concurrent (combined odd ratio = 0.87, 95% CI = 0.84-0.89, p < .001) and incident (combined odd ratio = 0.90, 95% CI = 0.85-0.96, p = .001) headaches. Higher conscientiousness (combined odd ratio = 0.90, 95% CI = 0.86-0.94, p < .001) and openness (combined odd ratio = 0.95, 95% CI = 0.90-0.99, p = .025) were associated with a lower probability of reporting concurrent headaches. Agreeableness was unrelated to headaches. Sex was not a consistent moderator. CONCLUSIONS: The present study provides robust evidence that neuroticism and introversion are risk factors for headaches in concurrent and prospective analyses across multiple cohorts.

Personality Traits and Memory: A Multilevel Analysis Across 27 Countries From the Survey of Health, Ageing and Retirement in Europe.

Personality traits are associated with memory in older adulthood: Individuals higher in conscientiousness and openness and lower in neuroticism tend to perform better on memory-recall tasks. We conducted a preregistered study to replicate these associations in a large, multinational cohort and test whether the associations varied by national-level socioeconomic indicators (e.g., per capita gross domestic product). Multilevel modeling was used to analyze data from 71,566 individuals (age: M = 67.9 years, SD = 9.5; 57% women) across 26 European countries and Israel. Higher conscientiousness, openness, and extraversion and lower neuroticism were associated with better memory performance, even when analyses accounted for risk factors including diabetes, hypertension, obesity, emotional disorders, and sleeping problems. Consistent with the resource-substitution hypothesis, results showed that higher conscientiousness and agreeableness and lower neuroticism were associated with better memory in countries with lower gross domestic product. This pattern suggests that psychological (trait) resources may help compensate for country-specific disadvantaged contexts.

Self-reported and mother-rated personality traits at age 16 are associated with cognitive function measured concurrently and 30 years later.

BACKGROUND: Models of personality and health suggest that personality contributes to health outcomes across adulthood. Personality traits, such as neuroticism and conscientiousness, have long-term predictive power for cognitive impairment in older adulthood, a critical health outcome. Less is known about whether personality measured earlier in life is also associated with cognition across adulthood prior to dementia. METHODS: Using data from the British Cohort Study 1970 (N = 4218; 58% female), the current research examined the relation between self-reported and mother-rated personality at age 16 and cognitive function concurrently at age 16 and cognitive function measured 30 years later at age 46, and whether these traits mediate the relation between childhood social class and midlife cognition. RESULTS: Self-reported and mother-rated conscientiousness at age 16 were each associated with every cognitive measure at age 16 and most measures at age 46. Self-reported openness was likewise associated with better cognitive performance on all tasks at age 16 and prospectively predicted age 46 performance (mothers did not rate openness). Mother-rated agreeableness, but not self-reported, was associated with better cognitive performance at both time points. Adolescent personality mediated the relation between childhood social class and midlife cognitive function. CONCLUSIONS: The current study advances personality and cognition by showing that (1) adolescent personality predicts midlife cognition 30 years later, (2) both self-reports and mother-ratings are important sources of information on personality associated with midlife cognition, and (3) adolescent personality may be one pathway through which the early life socioeconomic environment is associated with midlife cognition.

Personality pathways to mortality: Interleukin-6 links conscientiousness to mortality risk.

Personality is associated consistently with mortality hazards, but the physiological pathways are not yet clear. Immune system dysregulation may be one such pathway due to its role in age-related morbidity and mortality. In this preregistered study, we tested whether interleukin-6 (IL-6) and C-reactive protein (CRP) mediated the associations between personality traits and mortality hazards. The sample included 957 participants (M ± SD = 58.65 ± 11.51 years; range = 35-86 years) from the Midlife in the United States Survey that had 14 years of follow-up. Higher conscientiousness was associated with lower mortality hazards, with each one standard deviation higher conscientiousness associated with a 35% lower mortality risk. IL-6, but not CRP, partially mediated this association, with IL-6 accounting for 18% of this association in the fully adjusted model. While there was initial evidence that the biomarkers mediated both neuroticism and agreeableness and mortality risk, the indirect effects were not significant when controlling for the sociodemographic variables. Taken together, higher conscientiousness may lead to a longer life partially as a result of lower IL-6. This work highlights the importance of biological pathways that link personality to future mortality risk.