Early bonds, digital ties, and sacred shields : life course social and psychological predictors of cognitive health in later life.

As the global population continues to age, cognitive health has emerged as a pressing public health priority. While much research has focused on the biomedical explanations for cognitive aging, an increasing body of scholarship emphasizes the role of social and psychological experiences in shaping cognitive outcomes. Drawing on the life course perspective and the stress process model, this dissertation utilizes national longitudinal data from the National Longitudinal Survey of Youth (NLSY) and Health and Retirement Study (HRS) to examine how various social and psychological factors across the life course influence cognitive health in later life. The first empirical chapter investigates the long-term cognitive impact of early-life parent-child relationships. Results show that parental love and affection during childhood is associated with better self-rated memory in later life, while negative parental relationship predicts worse memory. Mediation analyses further reveal that these associations operate, in part, through psychological pathways. Specifically, higher self-esteem and greater sense of control in adulthood significantly mediate the relationship between positive parental relationship and better later-life memory. The second chapter focuses on social media engagement among older adults and its influence on cognitive health trajectories. Growth curve models show that while social media users tend to report lower cognitive function at baseline, those who engage actively and interactively on social media exhibit a slower rate of cognitive decline over time. Gender-stratified analyses further indicate that the cognitive benefits of active social media use is especially pronounced among older women. The third empirical chapter explores the cognitive effects of stress exposures and the moderating role of religious involvement. Findings show that high levels of chronic stress, financial hardship, and everyday discrimination are associated with worse cognitive function at baseline. Religious attendance and perceived importance of religion significantly buffer the negative impact of financial hardship and discrimination on baseline cognition. Overall, this dissertation contributes to a better understanding of the modifiable psychosocial risk and protective factors for cognitive health in later life, offering valuable insights for policies and interventions aimed at promoting healthy cognitive aging.