Facebook secretly experimented with the moods of 700,000 of its users

"...Unbelievable as it might seem, Facebook dosed the feeds of unknowing Facebook users with negative content to see if it would make the posts written by said Facebookers more negative. The researchers believe that it did. The mood of the posts seen in the feeds of the experiment’s subjects moved like a “contagion” (the researchers’ word, not mine) into the posts of said subjects. The inverse, too, was true, the researchers say. Facebook actually messed with the moods of its users..."

[venturebeat.com...]

The article cites a report to the (US) National Academy of Sciences titled: Experimental evidence of massive-scale emotional contagion through social networks, by Adam D. I. Kramer, Core Data Science Team, Facebook, Inc., Jamie E. Guillory of the Center for Tobacco Control Research and Education, Univ. of CA, San Francisco and Jeffrey T. Hancock, Dept of Communication and Information Science, Cornell University, Ithaca, NY.

The researchers state that the significance of the "experiment", (aka - messing with 689,003 people's moods during the week of January 11–18, 2012), was;

"We show, via a massive (N = 689,003) experiment on Facebook, that emotional states can be transferred to others via emotional contagion, leading people to experience the same emotions without their awareness. 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."

Full report is here -- [pnas.org...] -- but the essence was they filtered "negative" or "postive" messages off people's news feeds to get them to react negatively or positively.

If anything really bad happened to you diring the week of January 11–18, 2012 -- and you had spent a lot of time on Facebook that week --- this may be why...

Also reported in The Atlantic (and discusses legality of "experiment") -- [theatlantic.com...]