The New Scientist reports this morning that, “Like an influenza outbreak, happiness – and misery too – spread through social networks, affecting people through three degrees of separation. For instance, a happy friend of a friend of a friend increases the chances of personal happiness by about 6% (see graphic). Compare that to research showing that a $5000 income bump ups the odds by just 2%, says James Fowler, a political scientist at the University of California, San Diego, who led the new study.”

“Even people we don’t know and have never met have bigger effect on our mood than substantial increases in income,” he says. He and colleague Nicholas Christakis, of Boston’s Harvard Medical School, made the connection by mining 53,228 social connections between 5124 people who took part in a decades-long clinical study.

This study employed similar methods to those used to study smoking and obesity as part of the Framingham Heart Study, the research subjects recorded social contacts and health status as part of the long-term clinical study. Social links between participants allowed the investigators to map the spread of happiness — one item on the psychological questionnaire included in the study.

Even more than smoking and obesity, happiness spreads best at close distances, they found. A happy next-door neighbour ups the odds of person happiness by 34%, a sibling who lives within 1 mile (1.6 kilometres) by 14%, and a friend within half a mile by a whopping 42%.

The effect falls off through the network, with friends’ happiness boosting the chances of personal happiness by an average of 15% and friends of friends by 10%. As with obesity and smoking, Fowler and Christakis detected no effect beyond three degrees of separation.

And the sociological commentary…

Ruut Veenhoven, a sociologist at Erasmus University in Rotterdam, Netherlands, editor of the Journal of Happiness Studies, and curator of the World Database of Happiness agrees. “Happy people are typically more involved, are nicer to their kids and their dog, and live longer,” he says.

The study, which he describes as “terribly creative”, might even help people improve their daily lives. “If you want to make people happier, you know at least how it spreads.”

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