As people age, staying socially connected becomes harder—even though social engagement is essential for both mental and physical health. A new study from Nanyang Technological University in Singapore sheds light on why older adults may struggle with sociability.
The researchers found that natural changes in the brain’s internal communication patterns may be the key reason older people become less socially active.
Sociability refers to how well someone communicates, manages emotions, and engages in social situations. While it’s normal for this ability to decline slightly with age, for some older adults—especially those living alone—it can lead to loneliness and isolation, which in turn increases the risk of depression, cognitive decline, and even physical illness.
The study, published in PLOS One, explored how brain function might explain this decline. Researchers used data from 196 healthy adults aged 20 to 77 who took part in the Leipzig Study for Mind-Body-Emotion Interactions.
Each participant completed a sociability questionnaire and had a resting-state brain scan using fMRI (functional magnetic resonance imaging), which measures brain activity when a person is not engaged in any specific task.
The brain scans revealed two key networks of brain connections that change with age—and both were linked to lower sociability.
The first was called the age-positive network (APN). In this network, certain brain areas became more connected as people aged. This increased connectivity was linked to lower sociability. The APN mainly involved connections between brain regions responsible for emotion (limbic-insular areas), attention, and movement.
The second was the age-negative network (ANN). In contrast, connections in this network grew weaker with age, and this decline was also linked to lower sociability. The ANN included brain areas involved in thinking, memory, self-reflection, and control (such as the frontoparietal network, default mode network, and subcortical regions).
Through a method called mediation analysis, the researchers showed that changes in both networks fully explained the connection between aging and reduced sociability. In other words, these brain changes weren’t just part of the story—they were the entire story.
As the APN got stronger and the ANN got weaker with age, people’s ability to manage emotions, engage in conversation, and maintain confidence in social settings appeared to decline.
These brain changes may disrupt the natural balance between how different parts of the brain work together. Normally, the brain’s functional networks are well-organized—each network works mostly within itself.
But with age, this organization begins to break down. This desegregation makes communication between regions less efficient and may lead to trouble regulating emotions or participating in meaningful conversations.
The findings support the “social brain hypothesis,” proposed by anthropologist Robin Dunbar, which suggests that the human brain evolved to support complex social interactions. As brain function changes with age, so too does our capacity for social engagement.
The researchers say this insight could be helpful for older adults and their caregivers. By understanding that changes in sociability may be a natural result of how the brain ages, families, friends, and health professionals can offer more compassion and support.
They also suggest that psychoeducation—teaching people about these brain-related changes—may help older adults adapt their social behavior and preserve relationships later in life.
In short, this study shows that the decline in sociability many older adults experience may not be due to personal failure or disinterest—it may simply reflect how the aging brain works. Recognizing this can help society support older adults in staying socially active and emotionally healthy.
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The research findings can be found in PLOS One.
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