This week in social media, Facebook released a diversity report in line with the rest of Silicon Valley -- i.e., its employees are mostly white men. It also announced two secret projects: one that's impressive, and another that will make you feel like a lab rat. Meanwhile, Pinterest added a fun location-based feature, and Twitter beats Facebook at live World Cup updates. It's time for Social Media Saturday!

Facebook

Not Very Diverse...

Facebook followed the likes of Google, Yahoo and LinkedIn by publishing its diversity statistics this week, as we previously reported. In the press release, Facebook Global Head of Diversity Maxine Williams admitted the company had "a long way to go" but said Facebook was "serious about building a workplace that reflects a broad range of experience, thought, geography, age, background, gender, sexual orientation, language, culture and many other characteristics." The company only released statistics on gender and race though.

According to the statistics, it indeed does have a long way to go: 57 percent of all Facebook were white, while Hispanic and Black minorities only made up a total of 6 percent; 31 percent of Facebook are women, but in technology-related positions, a whopping 85 percent of employees were men. On the senior level, about three out of every four Facebook employees were white men.

Read our in-depth report for more information on Facebook's diversity statistics and strategy.

...And Kind Of Creepy

The same week, Facebook announced details of two secretive projects you didn't know the company was working on.

In an exclusive report, Wired detailed how a small team of engineers moved the photos of some 200 million Instagram users from an Amazon cloud computing service into a Facebook-owned data center -- all without any Instagram users being the wiser.

"The users are still in the same car they were in at the beginning of the journey," Instagram's Mike Krieger said to Wired. "But we've swapped out every single part without them noticing." It's really quite impressive, considering there was only one major outage in April -- and the team insists it was unrelated to the data relocation. Be sure to check out Wired's exclusive for the full story, in depth.

Facebook Knows How to Make You Happy or Sad

But moving tens of billions of photos without a detectable change in quality of service for users isn't the only secret project publicized by big blue.

Scientists at Facebook published a paper in The Proceedings of the National Academy of Sciences, or PNAS, this week (via A.V. Club). It describes an experiment they carried out on hundreds of thousands of unknowing Facebookers that will probably give you the willies.

Facebook's (presumably) white men in lab coats manipulated the News Feed content of more than 600,000 unknowing lab rats, distorting the number of positive or negative terms seen by the users (who were randomly selected for the experiment).

What did the scientists find?

They can increase the positivity or negativity of a person's future postings depending on how positive or negative they make the News Feed. In a more cynical reading: Facebook can make you happy or sad at will, depending on what it shows you.

Facebook's scientists were actually testing an aspect of a well-known psychological phenomenon called "Emotional Contagion," where emotional states can be transferred to others through social networks. Emotional contagion was traditionally thought to spread only in-person through interaction with one's real-life "social network," and through nonverbal cues (gestures, facial expression, etc.). Facebook's experiment gives more credence to the emerging view that the phenomenon can take place through telecommunication as well without necessarily any direct person-to-person interaction at all.

Feel (potentially) violated? You agreed to let Facebook tinker with your emotional states when you claimed that you read the Terms of Service and agreed that Facebook can access your data for "internal operations ... data analysis, testing, research and service improvement." Another good reason to try to read those pesky terms whenever possible.

Twitter: Better at the World Cup than Facebook

While Facebook is messing with its users' heads, Twitter is apparently dominating live World Cup social news. In an in-depth look at how topics trend on Twitter compared to Facebook, Mashable's Seth Fiegerman found that Twitter's list of Trending Topics for the World Cup were generally up-to-date with breaking events and spot on, compared with Facebook's.

Fiegerman showed how the worldwide trending topics on Twitter would track with World Cup matches, close to real-time, while Facebook's more curated top trending topics would be quite behind the times -- along with featuring lots of other topics that certainly weren't as globally popular as the World Cup (but, then again, what is?).

Here's an example from Fiegerman checking Facebook halfway through the U.S. vs. Germany match:


No mention of the ongoing story, and the only two World Cup items on Ghana were between several hours and a full day old. Meanwhile, the phrase "finally Ronaldo" began trending on Twitter soon after Cristiano Ronaldo scored a goal.

Facebook is behind the times and doesn't track topics solely based on organic popularity by design, though. That's because the company is trying to algorithmically customize trending topics for each user -- not to mention populating News Feeds with a balanced and manageable assortment of engaging posts from the millions of possible items flying around the huge social network at any given moment.

And, of course, occasionally manipulating your emotions if it feels like it.