Not Seeing Double: Discordance in Disease, Function, and Their Longitudinal Associations in Monozygotic Twins

Life-course social connectedness: Comparing data-driven and theoretical classifications as predictors of functional limitations in adulthood

A life course perspective on social relationships highlights the importance of specific relationships at specific times in life, but analyses that account for life course trajectories in social relationships are rare. This study compares theoretical and data-driven approaches to classifying life course relationships, including multiple dimensions of social connectedness at different time points across the life course. We examine each approach's ability to predict later-life functional limitations, given that functional impairment is prevalent among middle-aged and older adults. Data were from three waves of the Midlife in the United States (MIDUS) study (n = 6909). Relationship variables (parental affection, parental discipline, social support, social strain, and positive relations with others) were from wave 1 or wave 2. Functional limitations were measured at wave 3. Results showed that the data-driven approach had more predictive power than the theoretical approach. Additionally, results suggested that including only positive relationship features was nearly as robust as including both positive and negative relationship features. Overall, the data-driven approach outperformed the theoretical approach and revealed relationship trajectories consistent with life course cumulative processes.