Social Networks and Cognitive Function: An Evaluation of Social Bridging and Bonding Mechanisms

Background and Objectives Social connectedness has been linked prospectively to cognitive aging, but there is little agreement about the social mechanisms driving this relationship. This study evaluated 9 measures of social connectedness, focusing on 2 forms of social enrichment—access to an expansive and diverse set of loosely connected individuals (i.e., social bridging) and integration in a supportive network of close ties (i.e., social bonding). Research Design and Methods This study used egocentric network and cognitive data from 311 older adults in the Social Networks in Alzheimer Disease study. Linear regressions were used to estimate the association between social connectedness and global cognitive function, episodic memory, and executive function. Results Measures indicative of social bridging (larger network size, lower density, presence of weak ties, and proportion of non-kin) were consistently associated with better cognitive outcomes, while measures of social bonding (close ties, multiplex support, higher frequency of contact, better relationship quality, and being married) largely produced null effects. Discussion and Implications These findings suggest that the protective benefits of social connectedness for cognitive function and memory may operate primarily through a cognitive reserve mechanism that is driven by irregular contact with a larger and more diverse group of peripheral others.