Facebook revealed that it had manipulated the news feeds of
over 689,003 users randomly selected users to change the number of positive and
negative posts they saw. It was part of a psychological study to examine how
emotions can be spread on social media.
Facebook's terms and conditions, which all users agree to,
allow them to carry out research of this kind without telling users they're
being experimented on.
The researchers found that moods were contagious. The people
who saw more positive posts responded by writing more positive posts.
Similarly, seeing more negative content prompted the viewers to be more
negative in their own posts.
The study concluded emotions expressed by friends, via
online social networks, influence our own moods, constituting, to our
knowledge, the first experimental evidence for massive-scale emotional
contagion via social networks.
Reference:
Mcneal. G. (2014). Facebook Manipulated User News Feeds To Create Emotional Responses. Retrieved from: http://www.forbes.com/sites/gregorymcneal/2014/06/28/facebook-manipulated-user-news-feeds-to-create-emotional-contagion/ [Last accessed 30th June 2014]Wei Ru