Inter-Individual Variability in Trajectories of Functional Limitations by Race/Gender.

Objective: Several theories emphasize that systematic inter-individual divergence is a key feature of cohort aging and evidence for accumulative social inequality over the life course. While many have documented widening health gaps with age between subgroups, such divergence is only one aspect of the broader social inequality based on race and gender. This paper examines patterns of inter-individual variability in trajectories of functional limitations within each race/gender.

Methods: Using data from the Health and Retirement Study (HRS)'s HRS cohort (born 1931-1941), I estimate growth curves of functional limitations with level-2 heteroscedasticity, allowing inter-individual variability to differ across four groups: white men, black men, white women, and black women. I examine race/gender differences in age-based pattern of inter-individual variability using interquartile range of estimated individual trajectories.

Results: Black men, white women, and black women have greater inter-individual variability in functional limitations than do white men. Inter-individual variability increases systematically with age at similar rates for all groups but black women.

Discussion: Functional limitations become more heterogeneous with age for the entire cohort and for white men, white women and black men. Future research should identify life course processes that generate the race and gender patterning of inter-individual variability in late-life health.