Abstract
Friendships are cited as important contributors to physical, mental, and cognitive health, but many studies rely on single-time-point measures and models that conflate within- and between-person variation. Using data from 23,248 middle-aged and older adults in the Health and Retirement Study, we applied advanced longitudinal models—specifically STARTS variants of ARTS and RI-CLPM—to examine reciprocal associations between friendship characteristics (number, contact frequency, quality) and health indicators (self-rated health, depression, cognition) over a 16-year period. Cross-lagged effects were consistently small, and more robust evidence emerged for health predicting friendship outcomes than the reverse. The best-fitting models accounted for occasion-specific variance, suggesting traditional lagged models may overestimate these effects. Our results raise doubts about strong causal claims linking friendships to health and underscore the need for more careful modeling of temporal dynamics. Findings highlight the importance of decomposing trait-like and state-like variation to clarify the role of friendships in healthy aging.
Get full access to this article
View all access options for this article.
References
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
