It may be time to ditch those lonely friends. A new study published in the December issue of the Journal of Personality and Social Psychology reveals that loneliness is contagious, and can spread to up to three degrees of separation (so, avoid lonely neighbors, too). The study finds that lonely people tend to cluster with other lonelies, heightening their sense of isolation. Lonely people are described as those who feel a constant and pervasive state of loneliness, compared with the average person who feels lonely only 48 days of the year. It may also go without saying that lonely people have fewer friends, and tend to lose more friends over time. Women, the study found, are more susceptible than men to feelings of loneliness.