Inspired by the collected data of 5,124 people in the Framingham Heart Study in 1948, Nicholas Christakis and James Fowler found that the study notes included subjects’ family and friends. After 5 years of extracting the data in the notes, the two researchers discovered that the entire social network of the small town was thoroughly chronicled within the notes.
Branching outside the original intent of the study, Christakis and Fowler found that behaviors were influenced more by social connections than hereditary predisposition. For instance, it was more likely – 171 percent more likely – for a person to become obese if people close to them became fat. The condition actually spread like a virus.
"Your friends who live far away have just as big an impact on your behavior as friends who live next door," Fowler says. "Even if you see a friend only once a year, that friend will still change your sense of what's appropriate. And that new norm will influence what you do."
The influence of close relationships on a person regardless of physical distance led the two to look into the impact of online social interactions on individual behavior. While most people have an average of 6 close friends, that social trait is not altered by the average 110 ‘friends’ a Facebook user has. Using data of a university’s student population of Facebook users, they found that close friendships were maintained along with a higher level of connection between “acquaintances,” regardless of distance.
The network of influence seems to be limited to three degrees: an individual’s behavior, or tendency to become overweight or quit smoking, is limited to what a friend of a friend of a friend does. Beyond that, the influence stops.
If a Facebook user is happy, the usual is to post a smiling photo, and friends will follow suit. And that happiness spreads. Cut off from social networking ties, a person will slip into loneliness, despair and depression.
"Your friends might make you sick and cause you to gain weight," Christakis says, "but they're also a source of tremendous happiness. When it comes to social networks, the positives outweigh the negatives. That's why networks are everywhere."