Loneliness is often described as a simple absence - of people, of connection, of companionship. But two new studies suggest it may be something more complex, and more consequential: not just how socially connected people are, but how they experience those connections in the first place.
A study published in JAMA Network Open introduces a concept researchers call social asymmetry - the gap between objective social isolation and the subjective feeling of loneliness. Drawing on data from 7,845 adults over age 50 in England, followed for an average of 13.6 years, the study finds that this mismatch is associated with increased risk of disease and death.
Participants who felt lonelier than their level of social connection would predict, labeled "socially vulnerable," faced a higher risk of all causes of mortality, cardiovascular disease and chronic obstructive pulmonary disease compared with those whose feelings and social circumstances were more aligned.
"Most public health messaging around loneliness focuses on expanding social networks. But what this study suggests is that connection alone isn't the whole story," said co-author Anthony Ong, psychology professor and director of the Human Health Labs in the College of Human Ecology. "Two people can have similar social circumstances and face very different health trajectories depending on how they experience those circumstances."
The finding complicates a common narrative about loneliness as simply a function of how many people are in one's life. Some participants who were socially isolated but did not feel lonely, a group researchers describe as "socially resilient," showed little increased risk for most health outcomes. By contrast, those who felt lonely despite having relatively strong social networks faced elevated risk.
In other words, it is not only the presence of social ties that matters, but how those ties are perceived.
The study also found that individuals with higher levels of social asymmetry - meaning a greater discrepancy between loneliness and isolation - had increased risk of cardiovascular disease and mortality even when accounting for demographic, behavioral and health factors. The effects were modest on an individual level but significant at the population scale.
"What's encouraging is that social asymmetry is measurable, which means we can potentially identify who's most at risk before the health consequences set in," Ong said.
If the JAMA study identifies the long-term consequences of this mismatch, a second study, published in the Nature journal Communications Psychology, offers a window into how it may arise and persist in daily life.
In that research, 157 adults were tracked intensively over 20 days, responding to smartphone prompts five times a day. At each interval, they reported how lonely they felt, whether they had interacted with others, how much they disclosed in those interactions, and whether they felt rejected or criticized.
The results suggest that loneliness operates less like a stable trait and more like a dynamic system.
Moments of loneliness were closely tied to perceptions of social threat - feeling excluded, criticized or devalued. Those perceptions, in turn, were associated with changes in behavior, including reduced social interaction and less willingness to share personal information. Over time, these patterns formed what researchers describe as self-reinforcing sequences, in which emotional states, perceptions and behaviors feed into one another.
"Loneliness isn't just something people carry with them; it shapes how they read social situations and what they do next," Ong said.
When someone feels lonelier than usual, they're more likely to perceive the next interaction as threatening, and that perception makes them pull back.
"It's like a flywheel: Once it's turning, each moment adds momentum, and the state becomes increasingly hard to slow without something deliberately interrupting the cycle," Ong said.
The study also found that individuals higher in chronic, or "trait," loneliness showed stronger and more persistent links between these elements, suggesting that for some people, the cycle may be particularly difficult to break.
Together, the two studies point to a shift in how loneliness is understood.
Rather than a simple lack of social contact, loneliness may reflect a deeper disconnect between experience and environment - one shaped by perception, reinforced by behavior and, over time, linked to physical health.
That perspective may help explain why loneliness can persist even among people who are not objectively isolated, and why increasing social contact alone does not always resolve it.
"These findings suggest that intervention may require more than expanding the size of a person's social network. When an individual's interpretation of social situations is organized around threat, new relationships may confirm rather than correct that expectation," Ong said. "Addressing loneliness will therefore require attention not only to the structural conditions that produce it, but also to the perceptual and behavioral dynamics that sustain it."
