Identifying the individual characteristics that predict which adults will develop obesity and diabetes is crucial. This study included national data from 902 participants (aged 25-75) in the Midlife Development in the U.S. (MIDUS) study. Participants completed the Big-5 personality trait measure in 1995-1996, and behavior/health variables between 2004-2009. We tested whether levels of certain personality traits would predict an elevated risk of diabetes via hemoglobin A1c (HbA1c) levels through eating behaviors. A structural equation modeling framework demonstrated good fit when testing indirect effects (CFI = 0.95; RMSEA = 0.05). Indirect effects revealed that higher levels of neuroticism predicted greater waist circumference and higher HbA1c levels due to an increased use of food to cope with problems (IE =0.10; p<0.05). Moreover, indirect effects were found for conscientiousness, albeit in a protective direction. Our findings suggest that personality traits may be an early predictor of behavior and thus long-term adverse health outcomes.

Increased body weight is a risk factor for poor health and shortened life expectancy. Thus, it is imperative to understand how body weight changes across adulthood and to identify factors that predict weight gain so effective prevention strategies can be implemented. It is well-known that eating habits and physical activity are two of the most important factors (along with genetic factors) contributing to weight gain. However, we seek to determine if personality levels predict weight gain because individual differences in personality are thought to be the root-cause of many behaviors related to weight gain. We utilized longitudinal data on over 6,000 adults (aged 20-75 at baseline) from the Midlife Development in the U.S. Study (MIDUS). The Big 5 personality traits, body weight, waist circumference, and body mass index were measured three times from 1995-2015. We estimated a growth curve model to determine whether each adiposity measure changed over 20 years, controlling for age, gender, and education. There was a significant increase in all adiposity measures over time. The rate of adiposity change over time varied among persons (random: weight b = 0.543; waist b = 0.008; BMI b = 0.009; p values < .05). Higher levels of neuroticism predicted this variability (fixed: weight b = 0.211; waist b = 0.027; BMI b = 0.029; p values < .05) such that those scoring higher in trait neuroticism had a steeper increase in all three adiposity measures. These findings suggest that personality traits are important in the progression of weight-gain in adults.

Throughout adulthood, people’s personalities typically change favorably such that agreeableness and conscientiousness increase, and neuroticism decreases. However, the impact of early life adversity on these changes in personality has yet to be examined. We utilized data from 6,382 community dwelling adults (ages 25–75) that completed 3-waves of the Midlife Development in the U.S. Study (MIDUS) in 1995–96, 2005–06, and 2013–14. Early life adversity was computed using 16 retrospective items assessing emotional and physical abuse, socioeconomic disadvantage, familial instability, and early-life poor health. Personality was assessed with the Big 5 MIDI measure. Latent growth curves confirmed there was significant variability in change over the ~20 year follow-up (all RMSEAS < .06; and CFI/TLI > .96). More specifically, higher levels of early adversity predicted higher initial levels of neuroticism, and lower levels of conscientiousness and extraversion. Additionally, higher adversity predicted a steeper decrease in neuroticism across 20-years (all p’s < .05). Examination of specific adversity types revealed that emotional abuse and having poor health at a young age were especially detrimental to personality development. This research provides evidence that high levels of adverse experiences in childhood predict unfavorable personality development throughout adulthood. Moreover, this research demonstrates that early life adversity, especially certain types, can have lifelong detrimental effects on development. Interventions for those who have experienced adversity should be implemented as early in life as possible to prevent suboptimal psychological development trajectories. Such interventions could improve life outcomes if personality development is more normalized.

Adverse childhood experiences (ACEs) are associated with increased risk of premature mortality, but it is not clear why. Individuals with ACEs tend to have lower self-acceptance and purpose in life, which may be pathways between ACEs and risk of premature mortality. We used participants from the Midlife in the United States Survey (N = 6218; M ± SD = 46.89 ± 12.94 years) to test whether these factors mediated the association between ACEs and mortality hazards over 24 years of follow-up. We employed a comprehensive ACEs measure which included 20 possible childhood adversities including emotional and physical abuse, household instability, socioeconomic climate, and health. ACEs significantly increased mortality risk. Self-acceptance and purpose both partially mediated the ACEs mortality risk relation. ACEs may impact mortality risk partially through lower self-acceptance and purpose. These factors may be useful targets in adulthood for individuals with ACEs that may lead to a longer life.