Loneliness is often seen as simply a lack—of people, companionship, or social contact. However, recent research suggests it’s more nuanced and impactful: it’s not just about how many social connections someone has, but how they experience them.

A study in JAMA Network Open introduces the concept of social asymmetry—the gap between objective social isolation and the subjective experience of loneliness. Using data from 7,845 adults over 50 in England, tracked for an average of 13.6 years, researchers found that this mismatch is linked to higher risks of illness and death.

Participants who felt lonelier than their social circumstances would suggest—termed "socially vulnerable"—had higher rates of mortality, cardiovascular disease, and chronic obstructive pulmonary disease compared to those whose feelings aligned with their social connections.

“Most public health efforts focus on increasing social networks. But this study shows that mere connection isn’t enough,” said co-author Anthony Ong, psychology professor and director of Human Health Labs at Cornell University. “Two people with similar social networks can experience very different health outcomes depending on how they perceive those connections.”

The study also highlighted that people who were socially isolated but did not feel lonely—labeled “socially resilient”—showed little increase in health risks. In contrast, those who felt lonely despite having active social networks faced higher risks.

In short, it’s not just the number of social ties that matters, but the quality of how people perceive and experience them. Measuring social asymmetry could help identify those most at risk before health problems arise.