Can you "catch a mood" from spending time on social media? Researchers from the University of California, San Diego believe so.
Their study, published in PLOS ONE, analysed over a billion anonymised status updates from more than 100 million Facebook users located in major US cities.
It took place over 1,180 days, between January 2009 and March 2012. The study found "positive posts beget positive posts," while negative posts resulted in more negative posts. However, positive posts appear more "contagious."
Researchers used automated text analysis through the software program Linguistic Inquiry Word Count to measure emotional content in Facebook posts. Names and words used in said posts were not viewed.
"Our study suggests that people are not just choosing other people like themselves to associate with but actually causing their friends' emotional expressions to change," said lead author James Fowler, professor of political science in the Division of Social Sciences and of medical genetics in the School of Medicine at UC San Diego. "We have enough power in this data set to show that emotional expressions spread online and also that positive expressions spread more than negative."
Plenty of information is available concerning how emotions spread among people, whether among friends, acquaintances or total strangers. However, there's not nearly as much information concerning emotions across in the digital world, though Fowler notes this is important to investigate as people are so involved with social media and the digital realm in general.
Fowler and his team used rainy weather as an experiment for the study. They found rain did change post "tenor," increasing the number of negative posts by 1.16% and decreasing the number of positive posts by 1.19%. While this isn't a huge change, researchers were looking for a random variable, such as rain, that could be used to measure changes in user posts and the posts of their friends. They analysed posts of friends in cities where it wasn't raining to determine if "rainy day" posts resulted in a shift.
Was there a change? Yes. According to the study, each additional negative post resulted in 1.29 more negative posts among a user's friends, while each additional positive post created an additional 1.75 positive posts among friends.
"It is possible that emotional contagion online is even stronger than we were able to measure," Fowler said. "For our analysis, to get away from measuring the effect of the rain itself, we had to exclude the effects of posts on friends who live in the same cities. But we have a pretty good sense from other studies that people who live near each other have stronger relationships and influence each other even more. If we could measure those relationships, we would probably find even more contagion."