Sex-specificities in the association between social network and cognition in older individuals.

Social engagement is thought to support reserve and resilience in aging, yet prior findings suggest it may relate differently, potentially even in opposite directions, in males and females. To further understand these differences, we investigated psychological and biological correlates of social network within each sex, and tested whether its association with cognition differs by sex. Social network was assessed in 104 older adults (age 73.77 ± 3.58, 60 females) using the Social Network Index (network size and number of high-contact roles), alongside perceived social support, perceived stress, cortisol levels, hippocampal volume, and cognition. While greater social network was associated with higher perceived social support in both sexes, it was associated with lower cortisol levels only in males, and with higher perceived stress and smaller hippocampal volume in females. Social network size interacted with sex on cognitive outcomes, such that a larger network was associated more strongly with better cognition in males compared to females. Post-hoc analyses revealed that a larger social network was associated with higher attention and executive functioning in males, but with lower episodic memory performance in females. Overall, these findings suggest that social network is differentially associated with stress-related outcomes across sexes. Social contacts, potentially through increased social responsibilities, may contribute to higher perceived stress in women despite broader psychosocial benefits. This pattern may contribute to the observed differential associations with cognition across sexes. These results underscore the importance of considering sex differences when promoting social network in the context of healthy cognitive aging.