In the spread of happiness, the researchers found clusters of “infected” and “uninfected” people, a pattern considered a “hallmark of the infectious process,” said Hill. “For happiness, clustering is what you expect from contagion rates. Whereas for sadness, the clusters were much larger than we’d expect. Something else is going on.”
Happiness proved less social than sadness. Each happy friend increased an individual’s chances of personal happiness by 11 percent, while just one sad friend was needed to double an individual’s chance of becoming unhappy.
Do bom Signal/Noise