Facebook quietly tweaked the news feeds of 1.9 million users before the 2012 US election so they would see more “hard news” shared by friends.

That change may have boosted voter turnout by as much as three percent, according to a little-known study first disclosed Friday by Mother Jones.

For the study, news articles that Facebook users’ friends had posted appeared higher in their feeds — the stream of status updates, photos and articles that show up when you first sign on to the site. The researchers wanted to see whether increasing your exposure to news stories shared by friends before an election would convince you to vote.

Facebook said the news stories being shared were general in nature and not political. They came were from a list of 100 top media outlets from the New York Times to Fox News, according to the Mother Jones story, written by Micah Sifry, a democracy activist.

Facebook shared the results with some academics, but said it did not publicly disclose the experiment until Mother Jones revealed its existence because the researchers are planning to publish an academic paper based on their findings.

Read the full article here.