Educational attainment and social isolation trajectories from midlife to later life in four high- and middle-income countries.

Social isolation is an important public health concern, yet its variation by educational attainment across life stages and sociocultural contexts is not well understood. This study uses harmonized longitudinal data from the Gateway to Global Aging Data (2010 to 2018) to examine trajectories of social isolation from midlife to later life in the United States, England, China, and Mexico. We analyze both an overall isolation index and four dimensions of isolation: partnership status, contact with children, contact with friends, and social participation. Growth curve models assess differences in social isolation trajectories across educational groups and whether these disparities change with age. Less educated adults experienced higher overall isolation in all four countries, with larger gaps in China and Mexico and smaller gaps in the United States and England. Educational disparities in overall isolation widened with age in the United States and Mexico, consistent with cumulative disadvantage processes over the life course, but remained stable in England and China. Domain-specific analyses show notable cross-national variation. Education-related differences in social participation and friend contact were consistent across contexts, while differences in family-based ties varied in direction and size. These findings document cross-national educational disparities in social isolation and highlight the importance of considering structural barriers and domain-specific patterns in future research and policy discussions.