Laura Mandaro

USA TODAY Network

SAN FRANCISCO — If you didn't see a lot of talk about Ferguson and Michael Brown on your Facebook feed, maybe that's because your Facebook friends were afraid you'd disagree.

The Pew Research Center on Tuesday said a study of nearly 2,000 adults on an earlier hot-button political issue – the massive leak by Edward Snowden of documents that showed the National Security Agency had spied on U.S. citizens – found those surveyed were less willing to discuss the issue in social media than they were in person, and that social media did not provide an alternate platform to talk about the story if they weren't willing to discuss it in person.

Those who used Facebook were more willing to share their views if they thought followers agreed with them -- not much of a surprise. More telling was how perceptions of online feedback influenced their real-life interactions. Facebook and Twitter users who thought their online network wouldn't agree were less likely to speak their minds, both online as well as in person.

SPIRAL OF SILENCE

This 'spiral of silence,' a term used pre-Internet to describe a lack of discussion around a policy issue, usually because of fear of isolation, may be happening on the major social platforms — and then bleeding over into physical interactions.

That's just the opposite of one commonly held view, especially heralded by tech leaders: That social platforms have provided a forum for people to discuss issues they might shy away from in person.

"We speculate that social media users may have witnessed those with minority opinions experiencing ostracism, ridicule or bullying online, and that this might increase the perceived risk of opinion sharing in other settings," wrote the report's authors.

#MIKEBROWN

The theme of why and how – or why not – people are discussing a political issue over social media has been thrown into the spotlight by the Aug. 9 shooting death of unarmed black teenager Michael Brown in Ferguson, Mo. by white police officer Darren Wilson.

Twitter users who had not customized their trending topics saw related hashtags, such as #ferguson and #MikeBrown, surge after Brown's death, which was followed by weeks of protests and some nights of violence. On some days, several related hashtags were among the most trending phrases on Twitter, as people commented and retweeted photos and Vine videos posted by people in Ferguson.

For many, the Facebook experience was much different. Because Facebook's algorithm prioritizes stories in a user's timeline based on past stories that the user has liked, commented on or shared, it was possible for some users to see very little mention of the Ferguson protests. Even as the protests and police response blanketed Twitter and eventually traditional media like newspapers and cable news, #icebucketchallenge seemed more prevalent on Facebook.

The divergence was noted by several media outlets, including The Washington Post, tech blog GigaOm and BuzzFeed. The latter concluded: "blame the algorithms – or the users" – for Facebook's "breaking news problem."

But it's still not clear whether the seeming bifurcation between Twitter and Facebook can be only attributed to how Facebook's feed operates. Without any data from Facebook on how frequently certain subjects are discussed, there's no way to tell whether Ferguson was less discussed on Facebook versus Twitter. Or whether it just seemed that way to some observers.

If Ferguson was less discussed on Facebook, the Pew study may give some insight as to why: the commenting function in social networks, particularly Facebook, discourages conversation around social issues perceived as controversial to one's group of friends, acquaintances and social network.

FINDINGS: EASIER IN PERSON

Here are some more of the Pew study's findings. The survey of 1,801 adults was conducted in September and August 2013.

• 86% were willing to have an in-person conversation about the NSA surveillance programs, but just 42% of Facebook and Twitter users were willing to post about it.

• Of the 14% unwilling to discuss the Snowden-NSA story in person, only 0.3% were willing to post about it on social media.

• Facebook users were about twice as likely to join a discussion about the Snowden-NSA issue if they felt people in their network agreed with them.

• If Facebook users felt their online network agreed with them on the issue, they were more willing to discuss it with friends face-to-face. But they still were only 0.74 times as likely to voice their opinion as other people.

The research group said it was interested in the question because other Pew Research surveys around the time of the 2013 Snowden leaks found that Americans were divided over whether the leaks were justified and whether the surveillance policy was a good or bad idea.

The report's authors added the information leaked by Snowden, which at the time of the survey included information that Western intelligence agencies were monitoring some elements of phone and email communication, may have adjusted the way people communicated publicly.