The Buddy System: How Medical Data Revealed Secret to Health and Happiness

The Buddy System: How Medical Data Revealed Secret to Health and Happiness
By Jonah Lehrer 09.12.09
Obesity: Fat By Association
Smoking: Together We Quit, Divided We Fail
Happiness: Joy Is Contagious, Offline and on the Net
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A revolution in the science of social networks began with a stash of old papers found in a storeroom in Framingham, Massachusetts. They were the personal records of 5,124 male and female subjects from the Framingham Heart Study. Started in 1948, the ongoing project has revealed many of the risk factors associated with cardiovascular disease, including smoking and hypertension.

In 2003, Nicholas Christakis, a social scientist and internist at Harvard, and James Fowler, a political scientist at UC San Diego, began searching through the Framingham data. But they didn't care about LDL cholesterol or enlarged left ventricles. Rather, they were drawn to a clerical quirk: The original Framingham researchers noted each participant's close friends, colleagues, and family members.

"They asked for follow-up purposes," Christakis says. "If someone moved away, the researchers would call their friends and try to track them down."

Christakis and Fowler realized that this obsolete list of references could be transformed into a detailed map of human relationships. Because two-thirds of all Framingham adults participated in the first phase of the study, and their children and children's children in subsequent phases, almost the entire social network of the community was chronicled on these handwritten sheets. It took almost five years to extract the data—the handwriting was often illegible—but the scientists eventually constructed a detailed atlas of associations in which every connection was quantified.

The two researchers thought the Framingham social network might demonstrate how relationships directly influence behavior and thus health and happiness. Since the study had tracked its subjects' weight for decades, Christakis and Fowler first analyzed obesity. Clicking through the years, they watched the condition spread to nearly 40 percent of the population. Fowler shows me an animation of their study—30 years of data reduced to 108 seconds of shifting circles and lines. Each circle represents an individual. Size is proportional to body mass index; yellow indicates obesity. "This woman is about to get big," Fowler says. "And look at this cluster. They all gain weight at about the same time."

Obesity: Fat By Association
In 1948, fewer than 10 percent of Framingham residents were obese. By 1985, 18 percent were, and today about 40 percent are. What changed? Social norms of diet and physical appearance. "A bunch of people discovered fast food at the same time," social scientist Christakis says. "Then the network took over."

Obese person*
Nonobese person*
Friendship/marital connection
Familial connectionUnlike a flu epidemic, which starts with one infection, the scattered cases of obesity on early network maps indicated a multicentric contagion.Obesity radiated outward from clusters of overweight people.The condition's virulent infection rate led to dramatic clumping as weight classes self-segregated.Having an obese spouse raised the risk of becoming obese by 37 percent. If a friend became obese, the risk skyrocketed by 171 percent.Lean individuals surrounded by obesity were rare.*Circle size corresponds to body mass index

Images based on graphics created by James Fowler and Nicholas Christakis

There's something strange about watching life unfold as a social network. It's easy to forget that every link is a human relationship and every circle a waistline. The messy melodrama of life—all the failed diets and fading friendships—becomes a sterile cartoon.

But that's exactly the point. All that drama obscures a profound truth about human society. By studying Framingham as an interconnected network rather than a mass of individuals, Christakis and Fowler made a remarkable discovery: Obesity spread like a virus. Weight gain had a stunning infection rate. If one person became obese, the likelihood that his friend would follow suit increased by 171 percent. (This means that the network is far more predictive of obesity than the presence of genes associated with the condition.) By the time the animation is finished, the screen is full of swollen yellow beads, like blobs of fat on the surface of chicken soup.

The data exposed not only the contagious nature of obesity but the power of social networks to influence individual behavior. This effect extends over great distances—a fact revealed by tracking original subjects who moved away from Framingham. "Your friends who live far away have just as big an impact on your behavior as friends who live next door," Fowler says. "Think about it this way: 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." An obese sibling hundreds of miles away can cause us to eat more. The individual is a romantic myth; indeed, no man is an island.

In September, Christakis and Fowler published their first book for a general audience, Connected: The Surprising Power of Our Social Networks and How They Shape Our Lives. Although their research is filled with abstruse equations, the two seem most excited when describing the grand sweep of their work. "The story of modern science is the story of studying ever smaller bits of nature, like atoms and neurons," Christakis says. "But people aren't just the sum of their parts. I see this research as an attempt to put human beings back together again."

Once upon a time, social interaction was bounded by space; we met only in person. But then communication became mediated by technology. From telegraph to telephone to email to Twitter, each innovation fed the same anxieties, as people worried that traditional forms of community were being destroyed. The telephone was ruining family life; we're neglecting our real friends for our so-called friends on Facebook.

But does technology actually change the nature of the social network? Or does it simply extend it? It has long been recognized, for instance, that the human capacity for close friendship is remarkably consistent. People from cultures throughout the world report between four and seven bosom buddies. "The properties of our social networks are byproducts of evolution," Christakis says. "The assumption has been that our mind can handle only so many other people."

On Facebook, though, the average user has approximately 110 "friends," which has led some scientists to speculate that the Web is altering the very nature of human networks. For the first time in history, we can keep track of hundreds of people. The computer, they say, is helping to compensate for the limitations of the brain.

Smoking: Together We Quit, Divided We Fail
In the early '70s, 65 percent of Framingham residents ages 40 to 49 smoked regularly. By 2001, only 22 percent consumed one or more cigarettes daily. But the smoke didn't clear at random: Friends and family had a decisive influence. "People quit together," Fowler says, "or they didn't quit at all."

Smoker*
Nonsmoker
Friendship/marital connection

Familial connectionSmokers were evenly distributed throughout Framingham's social network.Smokers and nonsmokers intermingled freely, and many of the town's most excessive tobacco users had plenty of nonsmoking friends.Clusters of smokers persisted, but many were socially isolated.Entire coveys of smokers stopped in unison.When smokers quit, their friends were 36 percent more likely to follow suit. The effect tapered with each degree of separation, becoming insignificant at four degrees.*Circle size corresponds to daily cigarette intake

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.

After analyzing thousands of photos, the scientists found that, on average, each student had 6.6 close friends in their online network. In other words, nothing has really changed; even the most fervent Facebook users still maintain only a limited circle of intimates.

"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.

And because we're social primates, such communities are essential. When we're cut off from our network, we slip into a spiral of loneliness and despair, which severely affects our health. "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." People, in other words, need people: We are the glue holding ourselves together.

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.

Happy Unhappy

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.

See All Comments
Posted by: Raghuvansh1
4 days ago1 Point
How can you came to conclusion on happiness, health from random survive one of the bogus social net work just like Face Book?These and other social net work arise from shallow lifestyle of American psyche.From very beginning American psyche was shal...
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Posted by: samagon
21 days ago1 Point
the human body needs exercise, we can't sit around all day and assume we won't get fat, fat is energy stored in our body for use, and if we don't use it we will be fat and shitty. good health is simple, exercise, no special diet, no water diet, no at...
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Posted by: williamthrilliam
28 days ago1 Point
It's simple, stop eating crap. Lean meats, veggies, nuts, berries, and oils. This means zero sugar and zero grain products (bread, Twinkies, you name it). You will loose weight, yes it is healthy. I have been doing this for about a year and I hav...
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Posted by: Agent037
29 days ago-1 Points
i cant believe i just wasted 5 minutes of my life reading this shit

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Posted by: jeffg1
29 days ago1 Point
it took you 5 minutes to read a half-page of text? maybe you should have put the big mac down.

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Posted by: schauhan
29 days ago1 Point
Ha ha, and another minute typing up your response :-)

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Posted by: luckyray
29 days ago1 Point
THis map shows visual of how contagious obesity is!! Hmm, I wonder if this is a virus or other harmless infection. This type of obesity caused by external agents has long since been suspected and partly proven with fair amount of skepticism. I strong...
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Posted by: ideazones
27 days ago1 Point
Virus is a metaphor. The contagion is social influence, not physical. You hang around with drug users long enough, you will use. You hang with large eaters, you will eat more. It is really pretty simple. Get it?

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Posted by: richardsr
20 days ago1 Point
Uh, actually.... http://www.physorg.com/news11898.html

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Posted by: Davidicus
29 days ago0 Points
I think is comes down to how you enjoy life, and what is expected of you, and some of us do not adjust to an aging body too well, diet habits need to change as we grow older, we have to be more conservative, when I think the opposite happens because ...

Comment

I did my Masters paper on the effects of social support on nurses. The criteria I used was a Burnout questionaire and a Depression questionaire. It turns out from my study that burnout and depression overlap. I had my subjects indicate how much social support they gave, and received, at home and at work, on a 0-10 scale. Depression is seen as a personal experience, while burnout is a professional happening. The main traits in depression are helplessness and hopelessness, along with a strong dose of negativity. Burnout is a gradual process also where one goes from emotional work exhaustion, to depersonalization (an emotional withdrawal from the patients), to a sense that you arent doing as good a job as you should be (and have done in the past). Theoretically one goes thru the stages of burnout gradually and smoothly, but that didnt happen in my study, as some were emotionally exhausted but didnt withdraw from the patients. Those were the 45 hospice nurses. They indicated pretty severe depression and emotional exhaustion but did NOT withdraw from their patients! The other 43 nurses were hospital nurses who worked with otherhealth professionals every day. Hospice nurses reported little and no support from their supervisors. They work in the patient homes individually most of the day and have little contact with other nurses or supervisors. It was also interesting that the hospice nurses that reported themselves as being the most spiritual reported less burnout, as they felt like they were helping the patients to a better place. Social support is very important in Nursing, as in most human endeavors.