Med-Tech  :  Health   RSS


By Jonah Lehrer Email 09.12.09

But Christakis and Fowler were skeptical of such claims. They knew that social habits are stubborn things. So they persuaded a university to let them analyze the Facebook pages of its students, devising a clever way to distinguish between casual friends and deeper emotional connections. Close friends, they hypothesized, would post pictures of one another on their Facebook pages, since the relationship wasn't purely virtual.


"On Facebook, you've got a few close friends and lots of people you barely know," Fowler says. "Because the cost of information transmission is so low"—that is, the site makes it easy to communicate—"we end up staying in touch with more acquaintances. But that doesn't mean we have more friends."

Although the scientists are fascinated by the online world—"Facebook could become a revolutionary data set for people studying networks," Fowler says—their central research tool remains those handwritten papers salvaged from the Framingham Heart Study. In the four years since Christakis and Fowler built their first social map, they've published several groundbreaking papers documenting the network's influence on everything from cigarette addiction to happiness. In some cases, they've found that the impact of networks disappears abruptly after three degrees of separation. (In other words, if a friend of a friend of a friend stops smoking, then we are also significantly more likely to quit. But more-distant relationships have no effect; they are beyond the "social frontier.")

Although Christakis and Fowler have begun to study the variables, such as genetics, that determine a person's place within a social network—whether we're in the well-connected center or exiled to the fringe, which reflects popularity—they emphasize that there is no ideal social location. During a flu epidemic, the periphery is the safest place, since people with fewer connections are less exposed to the virus. But being on the fringe also reduces access to gossip and resources, which radiate out from the center. Because networks transmit the stuff of life—from happiness to HIV—evolution has generated a diversity of personality traits, which take advantage of different positions within the group. There are wallflowers and Wilt Chamberlains, shy geeks and "super-connectors." According to Christakis and Fowler, there is no single solution to the problem of other people. Individual variation is a crucial element of every stable community, from the Aborigines of Australia to the avatars of Second Life.


Happiness: Joy Is Contagious, Offline and on the Net

Studying the self-reported moods of Framingham subjects, Christakis and Fowler found that happy people have happy friends (and unhappy people, unhappy friends). Examining smiles in Facebook portraits, they found the same pattern: Even online, social networks gather around joyful expressions.

Each happy friend increased an individual's probability of being happy by 9 percent. An extra $5,000 in income raised it only 2 percent.
Even perfect strangers three degrees of separation away—friends of friends of friends—exerted a significant uplifting influence.
Unhappy people at the center of the network are more likely than those at the periphery to become happy in the future.
On average, smiling Facebook members reported 15 percent more close friends than their dour peers.
According to an analysis of Facebook, people who smiled in their profile photos tended to cluster with other smilers.
Emotions spread especially well through the online network, so it's a good bet this person will eventually post a smiling portrait.

Contributing editor Jonah Lehrer (jonah.lehrer@gmail.com) wrote about the neuroscience of magic in issue 17.05.

Related Topics: