In a creative test of the power of negative experiences to spread within a social network, researchers in one study examined how unhappiness can spread through social media. In this study, researchers first evaluated both positive and negative emotions conveyed in people’s Facebook posts.24 Then they compared the frequency of these emotional expressions to the amount of rainfall in each poster’s city. As you might expect, people tend to post more negative emotions, and fewer positive emotions, on rainy days. In fact, in a large city, such as New York City, a rainy day leads to an additional 1,500 negative posts by those living in that city compared to on a nonrainy day.
But what is even more interesting about this study is that the researchers then examined how one person’s Facebook post could influence the expressions posted by friends in other cities. These findings again provide strong evidence for the power of emotional contagion within a network. In other words, having a friend post something negative on Facebook increases the likelihood of a negative post and decreases the likelihood of a positive post, by one’s own friends. To return to the New York City example, a rainy day in New York City not only yields another 1,500 negative posts by those living in the city (and experiencing the rain) but an additional 700 negative posts by friends living elsewhere (and not necessarily experiencing rain).