Alzheimer's disease (AD) is a major threat for the rapidly aging world population. AD is the leading cause of dementia and a major cause of death in developed countries. The disease puts a tremendous practical, emotional and financial burden on individuals and governments. Clinicians and researchers in the AD field face great challenges: the pathophysiological processes that cause AD are not well understood, definite diagnosis of AD requires autopsy, and therapeutic options are limited to treating the symptoms rather than the cause of the disease. Nevertheless, new insights into the earliest events that lead to development of AD increase hope that reliable diagnostics and efficacious therapies may emerge.
Objective Social connectedness is a modifiable lifestyle factor that delays age-related cognitive decline. Using cross-sectional, longitudinal, and experimental approaches, we examined whether theory of mind – inferring what others think or feel – is a potential mechanism underlying this relationship.
Methods In Study 1, 305 community-dwelling older adults participating in two different, but related, studies completed comprehensive measures of general cognition, theory of mind, and personal social networks. We examined whether theory of mind mediated the relationship between older adults' social connectedness and cognition. 110 of those participants completed follow-up social network interviews and cognitive assessments about 1.5 years later to determine whether baseline social connectedness and theory of mind predicted cognitive change. In Study 2, 55 other older adults completed a procedural discourse task targeting a close and distant network member. We predicted that higher theory of mind would be reflected through providing more details to distant, versus close, others, especially among older adults with larger, less interconnected, personal social networks.
Results Results revealed that theory of mind accounted for 32% of the relationship between social connectedness and overall cognition, even when covarying age, gender, education, and a control task. The effects were particularly robust for episodic memory and language. Longitudinal analyses replicated this pattern. In Study 2, older adults with larger, less dense social networks provided more details to distant versus very close network members.
Discussion Together, these results suggest that theory of mind may provide the mechanism through which social connectedness confers cognitive resilience associated with slower cognitive decline.
