Back in January of 2012, those geeks at Facebook, along with scientific researchers from Cornell University and UC San Francisco put their eggheads together and created an  experiment to study a phenomena called emotional contagion. It is kind of the same theory which says that you will be more positive when you surround yourself with positive people and conversely more negative around Debbie Downers.

They changed the the algorithm of the News Feed for about 700,000 Facebook users. Giving one group of users more positive news pieces and another group more negative news stories. As it turns out Facebook is a mirror of human behavior, because just as in real life, the people who got more negative items, then tended to post more negatively and the receivers of positive News Feed stories posted positively.

Some Facebook users aren't so thrilled about being lab rats, but Facebook defended this study by saying they are all about improving their users experience and that they always carefully consider their research projects. Hmmm?