People’s happiness depends upon the happiness of others in their lives, says research published recently on bmj.com, a publication of the British Medical Association.
Because people with diabetes are prone to depression, it follows that we should make sure we are connected to happy, positive people.
“Happiness is not just an individual experience or choice, but is dependent on the happiness of others to whom individuals are connected directly and indirectly, and requires close proximity to spread,” say the authors in a press release. They cite as an example the finding that if you have a happy friend who lives within a mile, it increases your odds of happiness by 25 percent.
Professor Nicholas Christakis from Harvard Medical School and Professor James Fowler from the University of California, San Diego, analyzed data collected in the Framingham Heart Study to find out if happiness can spread from person to person and if clusters of happiness form within social networks*.
In the Framingham Heart Study**, 5,124 adults aged 21 to 70 were recruited and followed between 1971 and 2003. Participants were asked to identify their relatives, “close friends,” place of residence, and place of work to ensure that they could be contacted every two to four years for follow-up.
Additional data on mental health, collected using a depression rating scale during the original study, recorded agreement or disagreement with four statements “I felt hopeful about the future,” “I was happy,” “I enjoyed life,” and “I felt that I was just as good as other people.” In this BMJ paper, the authors defined happiness as a perfect score for all four statements.
Using statistical analysis, the researchers measured how social networks were correlated with reported happiness. They found that live-in partners who become happy increase the likelihood of their partner being happy by 8 percent. Similar effects were seen for siblings who live close by (14 percent) and neighbors (34 percent). Work colleagues did not affect happiness levels, suggesting that social context may curtail the spread of emotional states.
Interestingly, it is not only immediate social ties that have an impact on happiness levels. The relationship between people’s happiness can extend up to three degrees of separation (to the friend of one’s friends’ friend). Indeed, people who are surrounded by happy people are likely to become happy in the future.
Importantly, the researchers report that close physical proximity is essential for happiness to spread. A person is 42 percent more likely to be happy if a friend who lives less than half a mile away becomes happy. The effect is only 22 percent for friends who live less than two miles away, and the effect declines and becomes insignificant at greater distances.
The findings suggest that clusters of happiness result from the spread of happiness and not just from a tendency for people to associate with similar individuals.
The authors say in the press release, “Changes in individual happiness can ripple through social networks and generate large scale structure in the network, giving rise to clusters of happy and unhappy individuals.”
They conclude: “Most important from our perspective is the recognition that people are embedded in social networks and that the health and well-being of one person affects the health and well-being of others…Human happiness is not merely the province of isolated individuals.”
*The basic idea in social network analysis is that behaviors may spread over time from one person to another through immediate and more distant social contacts.
**The Framingham Heart Study, based in Framingham, Massachusetts, began in 1948 and is still ongoing. Much of what we know about the effects of lifestyle and treatments on the risk of heart disease has come from this longitudinal study. Started by the U.S. National Heart, Lung, and Blood Institute, the study has continued in collaboration with Boston University since the 1970s.