by Justin Jackson, Phys.org
Social engagement is a vital component of psychological and physical well-being linked to better health and a longer life, yet many older adults struggle to maintain relationships that support these outcomes.
New research from Nanyang Technological University in Singapore finds that changes in the brain’s intrinsic functional connectivity networks fully account for the decline in sociability observed with aging.
Sociability is a trait encompassing communication effectiveness, emotional management, and social assertiveness, that tends to diminish with age. Older adults, particularly those who live alone, are at increased risk of isolation, limiting forms of social participation.
In the study, “Intrinsic functional connectivity brain networks mediate effect of age on sociability,” published in PLO
Data were drawn from 196 healthy adults aged 20 to 77 participating in the Leipzig Study for Mind-Body-Emotion Interactions. Participants completed the Trait Emotional Intelligence Questionnaire’s Sociability subscale and underwent resting-state fMRI scans.
Network-based analysis identified two distinct sets of resting-state functional connections. One network, termed the age-positive network (APN), showed increased connectivity with age and was associated with lower sociability. APN connectivity was dominated by limbic-insular and ventral attention–somatomotor connections.
Second, the age-negative network (ANN) showed decreased connectivity with age, which was also associated with lower sociability. ANN connectivity included frontoparietal–default mode and subcortical–parietal connections.
Mediation analyses revealed that both networks independently and fully mediated the relationship between age and sociability. As people age, APN connectivity strengthens and ANN connectivity weakens, each correlating to sociability decreases.
Age-related changes in intrinsic brain connectivity appear to degrade socio-cognitive abilities required for initiating and sustaining social relationships. Functional network desegregation, marked by decreased within-network and increased between-network connectivity, may reduce emotion regulation, communicative competence, and confidence in social interactions.
Researchers propose that declining sociability reflects a neurobiologically grounded process of aging, consistent with Dunbar’s social brain hypothesis.
Psychoeducation addressing such normative shifts may assist older adults and caregivers in understanding personality change and promoting adaptive social behaviors later in life.
More information: Yuet Ruh Dan et al, Intrinsic functional connectivity brain networks mediate effect of age on sociability, PLOS One (2025). DOI: 10.1371/journal.pone.0324277
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