What new American scientific research says
The main conclusion of the study is that positive messages on Facebook "beget" other positive messages and negative messages beget other negative messages, with the "sticky" effect of positive ones being comparatively greater. Each negative message generates 1.29 more negative messages from one's friends, while each positive message "sparks" 1.75 additional positive messages.
The researchers, led by Christakis' regular collaborator, Professor James Fowler of the University of California-San Diego School of Medicine, who published the relevant paper in the journal "PLoS One", analyzed over a billion posts on the largest social network, made by more than 100 million users between 2009-2012.
In the digitally interconnected modern world, according to American researchers, emotional "contagion" is a reality through the cascading effect of social networks.
Among other things, the research showed that when it rains, the number of messages with a negative emotional charge increases by 1.16% and the number of positive ones decreases by 1.19%, which shows that people are susceptible even to changes in the weather, when it comes to their emotions.
Thus, Facebook can contribute to either a global “epidemic” of well-being or misery. People who live closer together, e.g. in the same neighborhoods or cities, exert greater online influence on each other.
According to the researchers, this “contagion” has major social consequences, as emotions spread in a synchronized manner on a large scale through social networks, thus leading to the creation of large groups of people who collectively become happy or unhappy, depending on the online influences they receive. This, the social scientists emphasize, “can create increasing instability in everything from political systems to financial markets.”.

