Subjective Socioeconomic Status in Daily Cognitive Functioning and Cognitive Aging
The primary purpose of this dissertation is to investigate to what extent objective and subjective socioeconomic status (SES) provide unique information regarding the impact of SES on cognitive aging trajectories, as well as daily individual variability and plasticity in cognitive functioning. For Study 1, two large samples were drawn from publically available data in the Health and Retirement Study (HRS) to examine cross-sectional performance on episodic memory and fluid reasoning tasks, and longitudinal change in general cognitive functioning across 6 years. Analyses of the cross-sectional sample indicated that subjective SES positively predicted performance on episodic memory and fluid reasoning tasks above and beyond the effect of objective SES. For both cognitive tasks, objective SES remained a significant predictor of cognitive performance after controlling for physical and mental health, but subjective SES was no longer a significant predictor. In the longitudinal sample, growth curve analyses suggested a small positive effect of increasing subjective SES to level of overall cognitive functioning beginning at around age 68, though this boost waned by age 90. This effect was maintained even while controlling for objective SES, BMI, self-rated health, and depressive symptoms. For Study 2, cognitive functioning across episodic memory and fluid reasoning domains were examined in a sample of 45 older adults who completed an initial baseline questionnaire including assessment of objective and subjective SES, and a 7-day `burst' repeated-measures design including cognitive tasks self-administered once a day. Overall, findings suggested that intraindividual variance in cognitive functioning across seven days was inversely related to overall mean performance for both episodic memory and fluid reasoning, such that individuals who showed more variability in performance tended to perform lower on cognitive tasks. Additionally, findings suggested that intraindividual variance in cognitive functioning is likely associated with both objective and subjective SES, though a number of the observed associations did not reach statistical significance. Collectively, these results suggest that an individual's perceptions of their SES may have fundamental impacts on later cognitive outcomes or, alternatively, that individuals may be able to provide a unique insight regarding their SES as not fully assessed by commonly used SES indicators.