A few weeks ago a friend described Facebook to me as a massive social experiment. At the time I didn't think much of it. News broke this weekend that the company had purposefully manipulated more than 600,000 people's News Feeds to test the psychological effects, however, and now my friend's description sounds pretty accurate.

The experiment, during which Facebook tweaked the user experience for about 689,003 people to show either predominantly positive or negative posts, revealed that the emotions you absorb over social media are indeed contagious.

In a scientific report published in the Proceedings of the National Academy of Sciences (PNAS) journal, the company's data engineers wrote that "emotional states can be transferred to others via emotional contagion, leading people to experience the same emotions without their awareness."

If the news that Facebook is secretly playing with your emotions makes you uncomfortable you may want to deactivate your account, because the company doesn't seem to see any issues with what it has done.

In a lengthy post to the social network, Facebook data scientist Adam Kramer defended the experiment, arguing that he and the rest of the small team failed to explain the reasons behind their tests. He notes that "the reason we did this research is because we care about the emotional impact of Facebook." He goes on to explain that the goal was to figure out what kind of posts make people unhappy. The reason, of course, is to make sure people stay happy and keep returning to Facebook. Kramer also says the effect was pretty minimal across the board, at least based on status updates written by those affected.

Even so, it's still shocking to see Facebook try out experiments like these. We know the site is always A/B testing different tweaks to its design and algorithm, but there's a difference between trying out a new look with a small subset of users and purposefully trying to make people happy or sad.

Hopefully Facebook will take note of the overwhelmingly negative public reaction to the news of its experiment, but for now the company doesn't seem to see any problem with its grand experiment.