Trajectories of Big Five Personality Traits: A Coordinated Analysis of 16 Longitudinal Samples.

This study assessed change in self-reported Big Five personality traits. We conducted a coordinated integrative data analysis using data from 16 longitudinal samples, comprising a total sample of over 60 000 participants. We coordinated models across multiple datasets and fit identical multi-level growth models to assess and compare the extent of trait change over time. Quadratic change was assessed in a subset of samples with four or more measurement occasions. Across studies, the linear trajectory models revealed declines in conscientiousness, extraversion, and openness. Non-linear models suggested late-life increases in neuroticism. Meta-analytic summaries indicated that the fixed effects of personality change are somewhat heterogeneous and that the variability in trait change is partially explained by sample age, country of origin, and personality measurement method. We also found mixed evidence for predictors of change, specifically for sex and baseline age. This study demonstrates the importance of coordinated conceptual replications for accelerating the accumulation of robust and reliable findings in the lifespan developmental psychological sciences.

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.

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.