Social scientists presented a message like this one to more than 60 million Facebook users during the 2010 Congressional elections.
A study of millions of Facebook users on Election Day 2010 has found that online social networks can have a measurable if limited effect on voter turnout.
The study, published online on Wednesday by the journal Nature, suggests that a special “get out the vote†message, showing each user pictures of friends who said they had already voted, generated 340,000 additional votes nationwide - whether for Democrats or Republicans, the researchers could not determine.
The scientists, from Facebook and the University of California, San Diego, said they believed the study was the first to show that social networks could have at least some impact on elections, and they added that the findings could have implications far beyond voting. For example, research is now being conducted on the use of social networks to help people lose weight.
Significantly if not surprisingly, the voting study showed that patterns of influence were much more likely to be demonstrated among close friends, suggesting that “strong ties†in cyberspace are more likely than “weak ties†to influence behavior. It also found an indirect impact from the messages: friends of friends were influenced as well.
“What we have shown here is that the online world and the real world affect one another,†said James H. Fowler, a professor of medical genetics and political science at the university.
On Nov. 2, 2010, the day of the nationwide Congressional elections, nearly every Facebook member who signed on - 61 million in all - received a nonpartisan “get out the vote†message at the top of the site's news feed. It included a reminder that “today is Election Dayâ€; a link to local polling places; an option to click an “I Voted†button, with a counter displaying the total number of Facebook users who had reported voting; and as many as six pictures of the member's friends who had reported voting.
But two randomly chosen control groups, of 600,000 Facebook members each, did not receive the pictures. One group received just the “get out the vote†message; the other received no voting message at all.
By examining public voter rolls, the researchers were able to compare actual turnout among the groups. They determined that the message showing friends who had voted was directly responsible for 60,000 more votes nationwide and indirectly responsible for 280,000 that were spurred by friends of friends - what they called “social contagion†effect.
Intriguingly, they also discovered that about 4 percent of those who claimed they had voted were not telling the truth.
Because only about 1 percent of Facebook users openly state their political orientation, the researchers said they could not determine whether political leanings had any influence on social networking and voting behavior.
The study was financed by the James S. McDonnell Foundation and by the University of Notre Dame's Science of Generosity Initiative, which is supported by the John Templeton Foundation.
Past studies have shown that a variety of methods for mobilizing potential voters have a disappointing effect. Knocking on doors is the most effective technique; e-mail is one of the least.
While the number of votes generated by the Facebook message was small compared with the overall turnout (about 90.7 million, or 37.8 percent of the voting-age population), the researchers said it could well have made a difference in individual races. After all, they pointed out, the 2000 presidential election was decided by less than 0.01 percent of the vote in Florida.
