Eileen K. Graham

Personality Predicts Mortality Risk: An Integrative Data Analysis of 15 International Longitudinal Studies

This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors of mortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HR<1.00) for openness, and U.S. studies showed a pattern of protective effects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability and reproducibility, especially for aging-related longitudinal research.

Future Directions in the Study of Personality in Adulthood and Older Age

Over the past 20 years, empirical evidence has brought about a change in the view on how, or even whether, personality traits change or develop in adulthood and later life. Now we know personality can and does change for many people, if not most. Changes in personality may occur due to biological or environmental factors. This paper presents key empirical findings on personality change in adulthood and provides evidence that personality change affects mental and physical health. Our goal is to provide a broad overview on personality change research that would be an invaluable resource for students and researchers. We organize this paper into 3 sections. The first is focused on techniques in analyzing personality change in adulthood and later life. The second is focused on personality change as an outcome; we explore what factors predict personality change. The third discusses a relatively novel idea: personality change as a predictor of mental and physical health. We conclude that more research on factors predicting personality change is needed and we provide suggestions on how research on personality change can progress.

Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003–2015)

BACKGROUND Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB. METHODS Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately. RESULTS Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p < .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation. CONCLUSIONS In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes.

Increases in Neuroticism May Be an Early Indicator of Dementia: A Coordinated Analysis

Objectives Although personality change is typically considered a symptom of dementia, some studies suggest that personality change may be an early indication of dementia. One prospective study found increases in neuroticism preceding dementia diagnosis (Yoneda et al, 2017). The current study extends this research by examining trajectories of personality traits in additional longitudinal studies of aging. Method Three independent series of latent growth curve models were fitted to data from the Longitudinal Aging Study Amsterdam (LASA) and Einstein Aging Study (EAS) to estimate trajectories of personality traits in individuals with incident dementia diagnosis (Total N = 210), in individuals with incident Mild Cognitive Impairment (N = 135), and in individuals who did not receive a diagnosis during follow-up periods (Total N = 1740). Results Controlling for sex, age, education, depressive symptoms, and the interaction between age and education, growth curve analyses consistently revealed significant linear increases in neuroticism preceding dementia diagnosis in both datasets and in individuals with MCI. Analyses examining individuals without a diagnosis revealed non-significant change in neuroticism overtime. Discussion Replication of our previous work in two additional datasets provides compelling evidence that increases in neuroticism may be early indication of dementia, which can facilitate development of screening assessments.

Frontal brain asymmetry, childhood maltreatment, and low-grade inflammation at midlife.

Frontal EEG asymmetry is thought to reflect variations in affective style, such that greater relative right frontal activity at rest predicts enhanced emotional responding to threatening or negative stimuli, and risk of depression and anxiety disorders. A diathesis-stress model has been proposed to explain how this neuro-affective style might predispose to psychopathology, with greater right frontal activity being a vulnerability factor especially under stressful conditions. Less is known about the extent to which greater relative right frontal activity at rest might be associated with or be a diathesis for deleterious physical health outcomes. The present study examined the association between resting frontal EEG asymmetry and systemic, low-grade inflammation and tested the diathesis-stress model by examining whether childhood maltreatment exposure interacts with resting frontal asymmetry in explaining inflammation. Resting EEG, serum inflammatory biomarkers (interleukin-6, C-reactive protein, and fibrinogen) and self-reported psychological measures were available for 314 middle-aged adults (age M=55.3years, SD=11.2, 55.7% female). Analyses supported the diathesis-stress model and revealed that resting frontal EEG asymmetry was significantly associated with inflammation, but only in individuals who had experienced moderate to severe levels of childhood maltreatment. These findings suggest that, in the context of severe adversity, a trait-like tendency towards greater relative right prefrontal activity may predispose to low-grade inflammation, a risk factor for conditions with inflammatory underpinnings such as coronary heart disease.

Who Are the Scrooges? Personality Predictors of Holiday Spending

The sharp increase in consumption over the holiday season has important economic implications, yet the psychology underlying this phenomenon has received limited attention. Here, we evaluate the role of individual differences in holiday spending patterns. Using 2 million transactions across 2,133 individuals, we investigate the relationship between the Big 5 personality traits on spending at Christmas. Zero-order correlations suggest holiday spending is associated with conscientiousness, neuroticism, and extraversion; the relationship with neuroticism persists after accounting for possible confounders including income and demographics. These results improve our understanding of how different personality traits predict how people respond to the environmental demands of the holiday season and have broader implications for how personality relates to consumer behavior.

Physical activity mediates the association between personality and biomarkers of inflammation

Objectives: The current study investigated whether personality traits and facets were associated with interleukin-6, C-reactive protein, and fibrinogen, and whether physical activity mediated the relationship between personality and biomarkers of inflammation. Methods: Personality was assessed in the Midlife Development in the United States study using the Multi-Dimensional Personality Questionnaire and Midlife Development Inventory personality scale. Data were included from 960 participants (mean age = 57.86 years, standard deviation = 11.46). Personality was assessed from 2004 to 2009. Serum levels of interleukin-6, fibrinogen, and C-reactive protein were assessed in 2005–2009 as part of the Midlife Development in the United States biomarkers subproject. Results: Lower neuroticism was associated with elevated interleukin-6, and achievement was associated with lower fibrinogen. Higher physical activity was associated with lower interleukin-6 and C-reactive protein. Mediation models suggested that physical activity mediated the associations between achievement and both interleukin-6 and C-reactive protein. Discussion: Physical activity is an important factor in the Health Behavior Model of personality and explains some of the associations between personality and inflammation. These findings contribute to the fields of aging and health by linking individual difference factors to markers of inflammation, and showing that these processes may function partially through specific behaviors, in this case physical activity.