Loneliness May Spread Contagiously

Laughter is supposedly contagious, but so is loneliness, according to a new article co-authored by Harvard Medical School professor and Pforzheimer House Master Nicholas A. Christakis.

In the article “Alone in the Crowd: The Structure and Spread of Loneliness in a Large Social Network,” Christakis and his co-authors argue that loneliness can be transmitted from person to person within a social network, and that even individuals who are included in social networks can feel lonely. According to Christakis, the article on loneliness takes a more technical approach to the loneliness theory discussed in his newest book.

“Most people think of emotions as only properties of individuals,” Christakis said. “Collective anger and fear of riots are typically considered group emotions, but we wanted to look at everyday emotions like loneliness.”

Christakis has received much attention for his research on social networks and was included in Time magazine’s list of the world’s most influential people in 2009.

In September, he and University of California at San Diego professor James H. Fowler ‘92 released a book titled “Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives.”

The article was a collaborative effort with Fowler as well as University of Chicago professor John T. Cacioppo that was published Monday in the December issue of The Journal of Personality and Social Psychology. Christakis, Fowler, and Cacioppo used a decade’s worth of data collected by the Framingham Heart Study, which began in 1971 and asked its subjects about their emotional state at regular intervals.

After reprocessing the data, the trio constructed the social networks using ties, such as familial or professional relationships, recorded in the original study.

The average American experiences loneliness 46 days each year, but this number is reduced by five percent for every friend he or she has, Christakis said.

The study found that loneliness is prevalent on the “edge” of the network and is transmitted between connected individuals, who eventually sever their connections with each other.

This result may demonstrate the need to address the spread of the loneliness contagion, which he said could negatively affect social cohesion.

“We need to pay attention to those at the edge­­­­­—franchise the disenfranchised,” he said, “The loss of ties because of loneliness could impact the vast fabric of humanity and cause an unravelling process like pulling the loose string of a sweater sleeve.”