The longitudinal association between social network composition and episodic memory in older adulthood: the importance of contact frequency with friends.

The composition of one's social network has been associated with cognition such that a greater proportion of family is associated with worse cognition compared to a greater proportion of friends. It is not clear whether this association between network composition and cognitive aging is driven by potential negative effects of family interactions or positive effects of friend interactions. Using the Health and Retirement Study (T1: 2006/2008, T2: 2010/2012, T3: 2012/2014), a longitudinal mediation model was conducted to test the effects of composition on episodic memory and latent change in memory through contact frequency with friends and family. Analyses revealed indirect effects of composition on both T2 memory and latent change in memory through contact frequency with friends. A greater proportion of family in one's network was associated with lower contact frequency with friends and in turn lower memory. Composition was also associated with higher contact frequency with family; however, contact frequency with family was not associated with memory. These findings suggest that spending time with family may not affect episodic memory in older adulthood, but spending time with friends may be beneficial. Potential mechanisms and implications regarding the importance of friendships in later life are discussed.