“Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study” by James H Fowler, associate professor, Nicholas A Christakis, professor had as objectives “To evaluate whether happiness can spread from person to person and whether niches of happiness form within social networks”. The abstract also says “Clusters of happy and unhappy people are visible in the network, and the relationship between people’s happiness extends up to three degrees of separation (for example, to the friends of one’s friends’ friends). People whoare surrounded by many happy people and thosewho are central in the network are more likely to become happy in the future. Longitudinal statistical models suggest that clusters of happiness result from the spread of happiness and not just a tendency for people to associate with similar individuals. A friend who lives within a mile (about 1.6 km)andwhobecomeshappy increases the probability that a person is happy by 25% (95% confidence interval 1% to 57%). Similar effects are seen in coresident spouses (8%, 0.2% to 16%), siblings who live within a mile (14%, 1% to 28%), and next door neighbours (34%, 7% to 70%). Effects are not seen between coworkers. The effect decays with time and with geographical separation. Conclusions People’s happiness depends on the happiness of others with whom they are connected. This provides further justification for seeing happiness, like health, as a collective phenomenon”.
Full paper is available on http://christakis.med.harvard.edu/pdf/publications/articles/095.pdf More information about their book “Connected” is available on http://connectedthebook.com