Life course socioeconomic position and cognitive aging in later life: A scoping review

Background and Objectives: Low socioeconomic position (SEP) throughout the life course is related to poorer cognitive health in later life, but debate ensues on the life course models for this association. To advance inquiry on the topic, we conducted a scoping review. Research Design and Methods: We examined the association between life course SEP and cognitive function in later life in observational studies-considering cognition both as a cross-sectional level and as a longitudinal trajectory across cognitive domains-and assessed whether the empirical evidence supported life course models. We focused on studies in the general population with cognition measured in the second half of life (45 +). Forty-two studies (21 datasets) were included representing 595,276 participants (201,375 across unique datasets) from 46 countries. Results: For cognitive level, studies consistently found associations between SEP at various stages of the life course, both in overall cognition and across specific cognitive domains. These associations were generally robust to confounding and mediating factors. For cognitive trajectory, studies showed inconclusive associations with SEP across life course and across cognitive domains. Results supported the sensitive period, pathway, and accumulation models, but not the critical period model. Results supported that education acts as a pathway (and potential mediator) in the association between early-life SEP and later-life cognition. Discussion and Implications: SEP throughout the life course has a robust association with later-life cognitive level, but not decline. Early-life cognitive enrichment for young people raised in socioeconomically disadvantaged households may reduce the SEP gap in cognitive functioning during later life.