Distinct social network structures and their cognitive and psychological correlates.

Social connectedness promotes healthy aging and is associated with lower risk for psychological disorders and cognitive decline. However, little is known about the mechanisms underlying these relationships, and whether different network features are associated with unique health benefits. We used comprehensive data from 386 community-dwelling older adults with and without cognitive impairment to test the relationship between psychological and cognitive function and their personal social networks. Data were collected using a multisite sampling strategy, and included detailed social network interviews and comprehensive measures of episodic memory, executive function, and language. Longitudinal effects were evaluated using a subsample at high-risk for decline, having either at least one copy of APOE ε4 or a current diagnosis of impairment (n = 118; average first follow-up = 2.28 years). Having smaller, affectively closer, and tightly connected social networks (i.e., social bonding) was modestly associated with positive psychological health. However, larger networks that contained weak ties, were more diverse with respect to social roles, and were less dense (i.e., social bridging) demonstrated robust effects on cognition. Longitudinal analyses demonstrated a sustained relationship between social bridging and cognition. Different kinds of social networks, reflecting distinct social mechanisms, may be associated with psychological and cognitive health.