In 2010 I co-wrote a book about happiness and well-being for schools. My colleagues – Sir John Jones, Joanna Reid – and I took the theory shaping positive psychology and asked what it might mean for a school. A school is a large(ish) social network. Social networks are important for our happiness and well-being. Below is an excerpt providing startling information about your networks.

For years it has been known that people in poorer countries tend to recover from mental illness more quickly because of reliable kinship networks. In January 2009, the British Medical Journal contained a study[i] that related better health to the quality and extent of social networks. The study was a follow-up to an earlier piece and showed how behaviours such as happiness spread over time from one person to another. This occurs through people’s ‘immediate and more distant social contacts’. The study, entitled ‘The Dynamic Spread of Happiness in a Large Social Network’, showed that happiness is a collective phenomenon. That is, happiness clusters in groups of people. And these groups can extend as far as three degrees of separation – to the friends of our friends’ friends! The study also showed that happiness can be spread through social networks and that the characteristics of the network will independently predict which individuals will be happier in the future. The key conclusion was that, ‘people’s happiness depends on the happiness of others with whom they are connected’.

According to the above study, a friend who is happy and who lives within a mile (about 1.6 km) of you increases the probability that you will be happy by 25 per cent. Similar effects were seen in co-resident spouses (if your partner is happy, you are 8 per cent more likely to be happy), siblings who live within a mile of each other (14 per cent) and next-door neighbours (34 per cent).

The study analysed results from the Framlington Heart Study that had traced 4,739 individuals between 1983 and 2003. The researchers knew that emotional states can be transferred directly from one individual to another by mimicry (sometimes called ‘emotional contagion’). This could take place in a number of ways including the copying of emotional behaviour, mimicking and replicating facial expressions and replicating mood. The research found that the participants of the study who were surrounded by many happy people and those who were central in their network were the most likely to become happy in the future.

Longitudinal statistical models suggest that clusters of happiness come about from the actual spread of happiness and not just from a tendency for people to associate with others who are of a similar mindset to themselves. Effects were not, however, seen between co-workers. The effect decayed with time and with geographical separation.

So, our own personal happiness depends on the happiness of others with whom we are connected.

[i] Fowler, J. and N. Christakis (2009), ‘Dynamic spread of happiness in a large social network – longitudinal analysis of the Framlington heart study social network’. British Medical Journal, 338, 23.