The intersectionality of life course socioeconomic status, race, and cognitive decline: An 18-year follow-up

Objectives: Studies have documented the impact of childhood socioeconomic status (SES) on cognition. However, research that simultaneously considers SES in varied life stages, the multidimensional mechanisms, and racial differences is relatively understudied. This study examines the intersectionality across age, SES, and race and its impact on cognitive trajectories. Methods: Using 8376 respondents aged 65+ from the 1998-2016 Health and Retirement Study, we used latent growth curve modeling to examine the effects of four life course models (latency, pathway, accumulation, and mobility) on 18-year trajectories of mental status and episodic memory. We further tested for differences in the links between SES and cognitive trajectories between black and white respondents. Results: Cognitive function declines with age and is interrelated with SES and race. Adulthood has a stronger effect on cognitive performance than childhood. However, linked positive childhood and adulthood SES contributes to positive cognition. Accumulated SES disadvantages were associated with lower cognition. Older adults with downward mobility and low SES throughout their lifespans had the lowest cognition scores. Life course models operated differently on trajectories of cognitive decline, yet the effects were particularly evident among older black respondents. Overall, those with socioeconomic advantages tended to have a slower decline in cognition, while a faster decline occurred for those with accrued disadvantages. Conclusions: Cognitive performance is a complex, longitudinal process intertwined with socioeconomic conditions and population heterogeneity shaped by life course contexts. Policies that facilitate healthy cognitive performance and address SES inequality could equalize health opportunities and address racial cognitive disparities later in life.