Lawson, K. M., Sutin, A. R., Atherton, O. E., & Robins, R. W. (2023). Are trajectories of personality and socioeconomic factors prospectively associated with midlife cognitive function? Findings from a 12-year longitudinal study of Mexican-origin adults. Psychology and Aging, 38(8), 749–762. https://doi.org/10.1037/pag0000755
Key Points
- The study examined how changes in Big Five personality traits and socioeconomic factors (per capita income, economic stress) across 12 years are associated with memory, mental status, and verbal fluency in middle adulthood.
- Higher initial levels of Openness, Conscientiousness, and Extraversion, and lower initial levels and smaller decreases in Neuroticism were associated with better subsequent cognitive function.
- Education level and trajectories of income and economic hardship across the 12 years were also robustly associated with cognitive function – higher education, income growth, and less economic hardship predicted better cognition.
- Socioeconomic factors tended to remain significantly associated with cognitive function even when personality traits were accounted for, whereas several personality associations became nonsignificant when socioeconomic factors were included.
Rationale
Cognitive impairment is a growing public health concern, but most research focuses on older adults (vs. middle adulthood) and non-Hispanic populations (Lawson et al., 2023). This study addressed these gaps by examining Mexican-origin adults in middle adulthood.
Prior research shows personality traits and socioeconomic factors are associated with cognitive function (Chapman et al., 2017; Zeki Al Hazzouri et al., 2011), but few studies look at changes in these predictors (Mueller et al., 2016).
Examining developmental trajectories can clarify when risk and protective factors for cognitive health emerge.
Method
- Data came from the 12-year longitudinal California Families Project following 883 Mexican-origin adults.
- Participants completed measures of the Big Five traits 6 times and measures of household income, economic hardship, and cognitive function (memory, mental status, verbal fluency) at the final wave.
- Latent growth curve models tested whether personality and socioeconomic trajectories predicted cognitive function.
Sample
- 883 Mexican-origin adults (63% female) with a median age of 38 at the first assessment. 99% were in middle adulthood at some point.
- Low average education (median 9th grade graduation) and income (median $32,500 household income). Most born outside the United States.
Statistical Analysis
- Latent growth curve models regressed the cognitive outcomes on the levels and slopes of personality traits and socioeconomic factors.
- Multiple group models tested differences by gender and nativity status.
Results
Here are the results for each research question:
Are the trajectories of Big Five traits across middle adulthood associated with later cognitive function?
Results:
- Higher initial levels of Openness, Conscientiousness, and Extraversion predicted better verbal fluency.
- Lower initial levels and decreases in Neuroticism predicted better memory, mental status, and verbal fluency.
Are education level and the trajectories of socioeconomic factors (per capita income and economic stress) across middle adulthood associated with later cognitive function?
Results:
- More education predicted better performance on all cognitive outcomes.
- Income growth predicted better cognition on all outcomes.
- Greater economic hardship predicted worse cognition on all outcomes.
Are personality and socioeconomic factors independently associated with later cognitive function?
Results:
- Socioeconomic factors remained significantly associated with cognitive function, even when personality was accounted for.
- Several personality trait associations became non-significant when socioeconomic factors were included.
Do the findings vary by type of cognitive function, gender, or nativity?
Results:
- The findings did not significantly differ for the cognitive outcomes, gender groups, or nativity status.
- The personality and socioeconomic associations tended to generalize across memory, mental status, and verbal fluency.
Insight
Personality traits earlier in adulthood can identify who may be at later risk for worse cognitive health before impairment emerges.
The study found that both higher initial levels of Neuroticism (i.e., greater anxiety, depression, emotional volatility) and smaller decreases in Neuroticism across the 12 years were associated with worse memory, mental status, and verbal fluency later in life.
Socioeconomic disparities have tangible consequences for minoritized groups’ cognitive function. Upward mobility may mitigate risk.
For example, the study found that Mexican-origin adults with lower education levels, less income growth over time, and greater economic hardship showed significantly worse performance on memory, mental status, and verbal fluency tasks later in life. These cognitive outcomes have real-world implications for occupational functioning, independent living, and quality of life.
Conversely, increases in socioeconomic resources predicted better cognitive health even decades later. This suggests that upward socioeconomic mobility could help buffer minoritized individuals against cognitive impairment and delay onset.
Strengths
- Used latent growth curve modeling with 6 assessments over 12 years to capture nuanced personality and socioeconomic development.
- Focus on an understudied Mexican-origin sample with low average education.
- Included multiple, well-validated measures of personality, socioeconomic factors, and cognitive function.
Limitations
- Most participants performed at ceiling levels on 3 of the 4 mental status tasks, restricting variance.
- Sample-specific factors (e.g., discrimination experiences, cultural values) relevant to cognitive health were unmeasured.
- Did not examine mechanisms linking predictors and cognitive function.
Implications
- Personality markers in young adulthood could inform early interventions to promote later cognitive health for minoritized groups.
- Targeting factors linking Neuroticism and cognition could inform interventions to promote cognitive health in minority communities.
- Policies and programs aimed at improving access to education and providing economic support may help reduce disparities in cognitive aging. Lifting members of marginalized communities into more advantaged socioeconomic positions could have intergenerational benefits by promoting cognitive health.
- Findings underscore the value of long-term longitudinal data to clarify risk and protective factors for cognition across adulthood.
References
Primary reference
Lawson, K. M., Sutin, A. R., Atherton, O. E., & Robins, R. W. (2023). Are trajectories of personality and socioeconomic factors prospectively associated with midlife cognitive function? Findings from a 12-year longitudinal study of Mexican-origin adults. Psychology and Aging, 38(8), 749–762. https://doi.org/10.1037/pag0000755
Other references
Chapman, B. P., Benedict, R. H., Lin, F., Roy, S., Federoff, H. J., & Mapstone, M. (2017). Personality and performance in specific neurocognitive domains among older adults. The American Journal of Geriatric Psychiatry, 25(8), 900–908. https://doi.org/10.1016/j.jagp.2017.03.006
Mueller, S., Wagner, J., Drewelies, J., Duezel, S., Eibich, P., Specht, J., Demuth, I., Steinhagen-Thiessen, E., Wagner, G. G., & Gerstorf, D. (2016). Personality development in old age relates to physical health and cognitive performance: Evidence from the Berlin Aging Study II. Journal of Research in Personality, 65, 94-108. https://doi.org/10.1016/j.jrp.2016.08.007
Zeki Al Hazzouri, A., Haan, M. N., Kalbfleisch, J. D., Galea, S., Lisabeth, L. D., & Aiello, A. E. (2011). Life-course socioeconomic position and incidence of dementia and cognitive impairment without dementia in older Mexican Americans: Results from the Sacramento Area Latino Study on Aging. American Journal of Epidemiology, 173(10), 1148–1158. https://doi.org/10.1093/aje/kwq483
Keep Learning
- What experiences might Mexican-origin adults have that affect both their personality development and cognitive health (e.g., discrimination)? How could these be measured?
- What types of early interventions could help promote healthier cognitive aging for marginalized communities? What barriers need to be addressed?
- How well do these findings generalize to other minoritized ethnic groups in the United States? What similarities and differences might be expected and why?
- If you could extend this study for another 10 years, what additional research questions would you want to examine regarding personality, SES, and cognitive function?
