CHICAGO, Dec. 1 (UPI) -- Loneliness, like the flu, can be contagious and spread among people, with the loneliest people getting lonelier and lonelier, U.S. researchers found.
Researchers at the University of Chicago, the University of California-San Diego and Harvard University used longitudinal data from a large-scale study tracking health conditions for more than 60 years.
The study, published in the Journal of Personality and Social Psychology, found that lonely people tend to share their loneliness with others and gradually over time, a group of lonely, disconnected people moves to the fringes of social networks -- getting lonelier still.
"We detected an extraordinary pattern of contagion that leads people to be moved to the edge of the social network when they become lonely," University of Chicago psychologist John Cacioppo said in a statement. "On the periphery people have fewer friends, yet their loneliness leads them to losing the few ties they have left."
By constructing graphs that charted the subjects' friendship histories and information about their reports of loneliness, researchers established a pattern of loneliness that spread as people reported fewer close friends.
The study also shows that as people become lonely, they become less trustful of others making it harder for them to form friendships.
