Cross-Lagged Modeling of Cognition and Social Network Size in the Sydney Memory and Ageing Study.

Findings support a co-constitutive view of cognitive function and social relationships in older age. Although both cognition and network size declined over time, slower than expected decline in language ability predicted less than expected contraction in social networks. A similar influence of network size on executive functioning indicated that relationships with friends and family outside of the home contributed significantly to the maintenance of higher order cognitive abilities in older late life. Diverse patterns of influence between cognitive domains and social network size over 6 years underscore the importance of assessing the complex and nuanced interplay between brain health and social relationships in older age.