Happiness is a collective -- not just individual -- phenomenon

December 04, 2008

BOSTON, Mass. (Dec. 4, 2008) --If you're happy and you know it, thank your friends--and their friends. And while you're at it, their friends' friends. But if you're sad, hold the blame. Researchers from Harvard Medical School and the University of California, San Diego have found that "happiness" is not the result solely of a cloistered journey filled with individually tailored self-help techniques. Happiness is also a collective phenomenon that spreads through social networks like an emotional contagion.

In a study that looked at the happiness of nearly 5000 individuals over a period of twenty years, researchers found that when an individual becomes happy, the network effect can be measured up to three degrees. One person's happiness triggers a chain reaction that benefits not only their friends, but their friends' friends, and their friends' friends' friends. The effect lasts for up to one year.

The flip side, interestingly, is not the case: Sadness does not spread through social networks as robustly as happiness. Happiness appears to love company more so than misery.

"We've found that your emotional state may depend on the emotional experiences of people you don't even know, who are two to three degrees removed from you," says Harvard Medical School professor Nicholas Christakis, who, along with James Fowler from the University of California, San Diego co-authored this study. "And the effect isn't just fleeting."

These findings will be published online Dec. 4 in the BMJ.

For over two years now, Christakis and Fowler have been mining data from the Framingham Heart Study (an ongoing cardiovascular study begun in 1948), reconstructing the social fabric in which individuals are enmeshed and analyzing the relationship between social networks and health. The researchers uncovered a treasure trove of data from archived, handwritten administrative tracking sheets dating back to 1971. All family changes for each study participant, such as birth, marriage, death, and divorce, were recorded. In addition, participants had also listed contact information for their closest friends, coworkers, and neighbors. Coincidentally, many of these friends were also study participants. Focusing on 4,739 individuals, Christakis and Fowler observed over 50,000 social and family ties and analyzed the spread of happiness throughout this group.

Using the Center for Epidemiological Studies Depression Index (a standard metric) that study participants completed, the researchers found that when an individual becomes happy, a friend living within a mile experiences a 25 percent increased chance of becoming happy. A co-resident spouse experiences an 8 percent increased chance, siblings living within one mile have a 14 percent increased chance, and for next door neighbors, 34 percent.

But the real surprise came with indirect relationships. Again, while an individual becoming happy increases his friend's chances, a friend of that friend experiences a nearly 10 percent chance of increased happiness, and a friend of *that* friend has a 5.6 percent increased chance--a three-degree cascade.

"We've found that while all people are roughly six degrees separated from each other, our ability to influence others appears to stretch to only three degrees," says Christakis. "It's the difference between the structure and function of social networks."

These effects are limited by both time and space. The closer a friend lives to you, the stronger the emotional contagion. But as distance increases, the effect dissipates. This explains why next door neighbors have an effect, but not neighbors who live around the block. In addition, the happiness effect appears to wear off after roughly one year. "So the spread of happiness is constrained by time and geography," observes Christakis, who is also a professor of sociology in the Harvard Faculty of Arts and Sciences. "It can't just happen at any time, any place."

They also found that, contrary to what your parents taught you, popularity *does* lead to happiness. People in the center of their network clusters are the most likely people to become happy, odds that increase to the extent that the people surrounding them also have lots of friends. However, becoming happy does not help migrate a person from the network fringe to the center. Happiness spreads through the network without altering its structure.

"Imagine an aerial view of a backyard party," Fowler explains. "You'll see people in clusters at the center, and others on the outskirts. The happiest people tend to be the ones in the center. But someone on the fringe who suddenly becomes happy, say through a particular exchange, doesn't suddenly move into the center of the group. He simply stays where he is--only now he has a far more satisfying sense of well-being. Happiness works not by changing where you're located in the network; it simply spreads through the network."

Fowler also points out that these findings give us an interesting perspective for this holiday season, which arrives smack in the middle of some pretty gloomy economic times. Examination of this dataset shows that having $5,000 extra increased a person's chances of becoming happier by about 2 percent. But that the same data also show, as Fowler notes, that "Someone you don't know and have never met--the friend of a friend of a friend--can have a greater influence than hundreds of bills in your pocket."

This is the third major network analysis by Christakis and Fowler that shows how our health is affected by our social context. The two previous studies, both published in the New England Journal of Medicine, described the social network effects in obesity and smoking cessation.
-end-
The research was funded by the National Institutes of Health/National Institute on Aging, a Pioneer Grant from the Robert Wood Johnson Foundation, and a contract from the National Heart, Lung, and Blood Institute to the Framingham Heart Study.

Written by David Cameron

Full citation:

BMJ, early online publication, December 4, 2008

Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study

James H Fowler(1), Nicholas A Christakis(2)

1-University of California, San Diego, San Diego CA
2-Harvard Medical School, Boston, MA

Harvard Medical School http://hms.harvard.edu has more than 7,500 full-time faculty working in 11 academic departments located at the School's Boston campus or in one of 47 hospital-based clinical departments at 18 Harvard-affiliated teaching hospitals and research institutes. Those affiliates include Beth Israel Deaconess Medical Center, Brigham and Women's Hospital, Cambridge Health Alliance, Children's Hospital Boston, Dana-Farber Cancer Institute, Forsyth Institute, Harvard Pilgrim Health Care, Hebrew SeniorLife, Joslin Diabetes Center, Judge Baker Children's Center, Immune Disease Institute, Massachusetts Eye and Ear Infirmary, Massachusetts General Hospital, McLean Hospital, Mount Auburn Hospital, Schepens Eye Research Institute, Spaulding Rehabilitation Hospital, and VA Boston Healthcare System.

Harvard Medical School

Related Happiness Articles from Brightsurf:

Happiness and the evolution of brain size
Serotonin can act as a growth factor for the stem cells in the fetal human brain that determine brain size.

The key to happiness: Friends or family?
Think spending time with your kids and spouse is the key to your happiness?

Hedonism leads to happiness
Relaxing on the sofa or savoring a delicious meal: Enjoying short-term pleasurable activities that don't lead to long-term goals contributes at least as much to a happy life as self-control, according to new research from the University of Zurich and Radboud University in the Netherlands.

When it comes to happiness, what's love got to do with it?
Researchers from Michigan State University conducted one of the first studies of its kind to quantify the happiness of married, formerly married and single people at the end of their lives to find out just how much love and marriage played into overall well-being.

Health and happiness depend on each other, Psychological Science says
New research adds to the growing body of evidence that happiness not only feels good, it is good for your physical health, too.

Happiness might protect you from gastrointestinal distress
Serotonin, a chemical known for its role in producing feelings of well-being and happiness in the brain, can reduce the ability of some intestinal pathogens to cause deadly infections, new research by UT Southwestern scientists suggests.

Spending on experiences versus possessions advances more immediate happiness
Consumers are happier when they spend their money on experiential purchases versus material ones, according to research from the McCombs School of Business at the University of Texas at Austin.

Braces won't always bring happiness
Research undertaken at the University of Adelaide overturns the belief that turning your crooked teeth into a beautiful smile will automatically boost your self-confidence.

In China, a link between happiness and air quality
In a paper published in the journal Nature Human Behaviour, a research team led by Siqi Zheng, the Samuel Tak Lee Associate Professor in MIT's Department of Urban Studies and Planning and Center for Real Estate, and the Faculty Director of MIT China Future City Lab, reveals that higher levels of pollution are associated with a decrease in people's happiness levels.

The 17 different ways your face conveys happiness
Human beings can configure their faces in thousands and thousands of ways to convey emotion, but only 35 expressions actually get the job done across cultures, a new study has found.

Read More: Happiness News and Happiness Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.