Facebook fiends got out the vote

WASHINGTON -- Here's something most politicians can "like": Facebook friends played a big role in getting hundreds of thousands of people to vote in 2010, a scientific study claims.

Facebook researchers and scientists at the University of California, San Diego, conducted a huge online experiment in the midterm congressional election to measure the political power of online peer pressure.

They found that people who got Facebook messages that their friends had voted were a bit more likely to go to the polls than those who didn't get the same reminder. And from there the effect multiplied in the social network, they reported in today's journal Nature.

The friend-prodding probably increased voter turnout by as much as 340,000 in the nonpresidential election that voted in a new Republican Congress, the scientists calculated. It could potentially change the outcome of close elections, they said.

"Our study is the first large-scale scientific test of the idea that online social networks affect real world political behavior," said study lead author James Fowler, a professor of medical genetics and political science at UC San Diego.

While pundits have pointed to social media-inspired revolutions in the Arab world, this is more verifiable scientifically, a controlled study comparing groups with different inputs. It's the voting equivalent of testing real drugs versus sugar pills.

Outside experts say the new study makes sense and fits with other research about how effective get-out-the-vote drives are, but say Fowler's numbers may be a bit high. That's because they factor in a large indirect effect, calculations which some didn't find as convincing.

Nearly every American of voting age who logged on to Facebook on Election Day 2010 was part of the experiment, though they didn't know it.

Most of them -- more than 60 million -- saw an announcement on top of their Facebook news feed: Today is Election Day. It showed how many Facebook users as well as their friends had clicked an "I voted" button and showed up to six pictures of those friends.

Researchers compared voter turnout with two groups that didn't get the same message. One group of 611,000 people got a generic announcement encouraging voting, but no pictures or count of friends. Another 613,000 didn't get any message.

Those who got the peer pressure message were less than half a percent (0.39 percent) more likely to vote than those who got no message or the generic one. That seems like a very small increase, but it is statistically significant and it adds up, Fowler said.

There was no difference in voting found between the generic and no-message groups. Nor was there any difference seen in friend-prompted turnout between self-identified conservatives and liberals, Democrats and Republicans.

Fowler and colleagues didn't just take the word of people who clicked the "I voted" button. They checked public voting records and found about 4 percent of those who said they voted hadn't really cast ballots.

Of those who saw the peer pressure posting, he calculated that 60,000 voted who wouldn't have. Another 280,000 voted who wouldn't have because their friends saw the online message and spread the get-out-the-vote word.