Linking the 1940 U.S. Census to the National Social Life, Health, and Aging Project: Novel Opportunity to Understand the Effects of Early-Life Residential Environment on Cognitive Aging.

Objectives: The 1940 Census is a valuable resource for understanding various aspects of historical populations in the United States. Recently, the National Social Life, Health and Aging Project integrated 1940 Census data into its extensive data set, providing researchers with an opportunity to explore new avenues of life course investigation. We leverage the newly introduced measures of childhood residential environment and evaluate their potential predictive utility in older adult cognitive functioning net of childhood and adulthood characteristics known to be key risk factors for poor cognition.

Methods: We analyzed 777 respondents who were children in 1940 (age <17) that have been linked to the 1940 U.S. Census. We used childhood geographic location, homeownership status, household composition, and parental nativity as predictors. Cognitive function was measured using the Montreal Cognitive Assessment.

Results: Regression analysis showed that growing up in an urban area was associated with better cognitive function, while being born in the South was linked to poorer cognitive function, even after controlling for childhood health, parental education, educational attainment, stroke, and smoking status. Additionally, childhood multigenerational household was associated with better cognitive function, and childhood family size was associated with poorer cognitive function. However, these associations became statistically insignificant with the inclusion of educational attainment. We did not find homeownership and parental nativity to be associated with cognitive function.

Discussion: The findings may shed light on the potential long-term effects of childhood circumstances on cognitive aging processes. Implications for current literature and directions for future research are discussed.