>Objectives: To evaluate whether happiness can spread from person to person and whether niches of happiness form within social networks.
Design: Longitudinal social network analysis.
Setting: Framingham Heart Study social network.
Participants: 4739 individuals followed from 1983 to 2003.
Main outcome measures: Happiness measured with validated four item scale; broad array of attributes of social networks and diverse social ties.
Results: 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 who are surrounded by many happy people and those who 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.
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.
Setting: Framingham Heart Study social network.
Participants: 4739 individuals followed from 1983 to 2003.
Main outcome measures: Happiness measured with validated four item scale; broad array of attributes of social networks and diverse social ties.
Results: 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 who are surrounded by many happy people and those who 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.
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.
What is already known on this topic
- Previous work on happiness and wellbeing has focused on socioeconomic and genetic factors
- Research on emotional contagion has shown that one person’s mood might fleetingly determine the mood of others
- Whether happiness spreads broadly and more permanently across social networks is unknown
What this study adds
- Happiness is a network phenomenon, clustering in groups of people that extend up to three degrees of separation (for example, to one’s friends’ friends’ friends)
- Happiness spreads across a diverse array of social ties
- Network characteristics independently predict which individuals will be happy years into the future
>Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study (BMJ 2008; 337:a2338)