Published online by Cambridge University Press: 21 December 2023
Socioeconomic disadvantage is a chronic stressor associated with several biological markers of health (e.g., inflammation) as well as early-onset cognitive aging. Studies examining socioeconomic status (SES) and its link with health outcomes exhibit no uniformity in the way in which SES is measured and defined. Also, studies have found that subjective socioeconomic status (SSES), defined by a subjective SES scale, was more consistently and strongly related to psychological functioning and health-related outcomes than objective socioeconomic status (OSES), defined by a composite score of education, household income, and occupation. The goal of the current study was to assess whether SSES mediates the relationship between OSES and neuropsychological test performance similarly across racial and ethnic groups.
Participants were 1,912 middle-aged older adults (13% non-Hispanic white, 17% non-Hispanic Black, 69% Hispanic/Latinx) from the Offspring study. Participants are the adult children of participants in the Washington Heights Inwood Columbia Aging Project, a community-based cohort study of aging and dementia representing the ethnic/racial diversity of upper Manhattan. Participants on average were 56.5 years of age and 67% were women. Measures of verbal learning and memory (SRT immediate and delayed recall), verbal fluency (animal and letter fluency), and attention/working memory (digit span forward and backward) were administered. OSES was characterized by years of formal education completed. SSES was measured by the MacArthur Scale of Subjective Social Status. The scale measures perceptions of one’s social standing relative to others. We conducted separate stratified mediation analyses for each neuropsychological outcome across each racial and ethnic group. All models were adjusted for age.
Participants with higher OSES demonstrated higher neuropsychological test scores (effect size associations ranged from .29 to .45) and reported higher SSES (b=.109 95% CI: .08, .14). Lower SSES was associated with lower neuropsychological test scores (effect-size range .06 to .13). In stratified analyses, the relationship between OSES and SSES was strongest for White participants (b=.13 [.01, .24]) compared with Latinx (b=.06 [.02, .11]) and Black (b=.06 [-.03, .16]) participants. Associations between SSES and neuropsychological outcomes were only reliable for White participants on SRT Immediate and Delayed Recall and Animal Fluency and for Black participants on Digit Span Forward. In mediation analyses, SSES mediated the relationship between OSES and Immediate Recall (indirect effect b=.18 [.001, .45]; 39% mediated), Delayed Recall (indirect effect b=.05 [.004, .09]; 44% mediated), and Animal Fluency (indirect effect b=.09 [.01, .20]; 22% mediated) for White participants. There was no evidence of mediation in Black or Latinx participants.
The relationship between OSES and SSES was strongest for White participants compared to Black and Latinx participants. Even though perception of social status predicted lower cognitive test scores among Black and Latinx adults, it is only a part of the indirect pathway linking OSES to cognitive function among White adults. It is likely that mechanisms related to tangible resources that benefit health (as opposed to perceived inequity) are in the pathway linking education to cognition among Black and Latinx, and thus intervening on systems of inequality throughout the life course has the most promise for improving brain health in those communities.