According to a study recently published in the Proceedings of the National Academy of Sciences (PNAS), data scientists for Facebook tweaked the News Feed algorithms for 689,003 users, manipulating the types of posts they saw on a daily basis. For one week in 2012, the algorithm filtered a disproportionately low number of either positive or negative posts on the users’ feeds.
The point was to see if emotions could be transferred virtually, just as they are transferred in face-to-face interactions. And sure enough, the scientists found that people who saw fewer positive posts on their News Feeds created fewer positive posts themselves. Conversely, the fewer negative posts people saw, the more positive they became online.
“Emotional states can be transferred to others via emotional contagion, leading people to experience the same emotions without their awareness,” wrote study authors Adam Kramer, Jamie Guillory, and Jeffrey Hancock. “We provide experimental evidence that emotional contagion occurs without direct interaction between people (exposure to a friend expressing an emotion is sufficient), and in the complete absence of nonverbal cues.”