Dynamic spread of happiness in a large social network

This study from the BMJ (British Medical Journal): Dynamic spread of happiness in a large social network: longitudinal analysis over 20 years in the Framingham Heart Study is about the ecology of joy

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.

So, as you experience joy, and you exhibit the signs of joy, people around you feel more joyful.