How do your friends plan to vote?

Most election polls take the political pulse of a state or nation by reaching out to citizens about their voting plans. Santa Fe Institute Professor Mirta Galesic says pollsters might also ask: how do your friends plan to vote?

In a new paper published in Nature Human Behavior, Galesic and co-authors—including Wandi Bruine de Bruin (Leeds Business School), former Santa Fe Institute Omidyar Fellow Marion Dumas (London School of Economics), and researchers from University of Southern California Dornsife—compared the results of these two polling methods from data gathered during the most recent presidential elections in the United States and France. They tapped into existing polling efforts to ask questions about an individual's friends alongside the traditional questions about themselves. In both countries, responses people gave about their friends led to more accurate predictions for the election outcomes than the information people gave about themselves.

"It is often assumed that people are biased in their evaluations of others, for instance thinking that your friends have the same opinions as you do," says Galesic. "We think that's not necessarily true, at least when it comes to people's close social contacts. Our other ongoing research shows that people know their family and friends quite well. After all, they depend on them for cooperation, learning, and all kinds of support."

Polls that ask people to comment on their social circles can improve prediction results for several reasons, says Galesic. They provide information about people who aren't explicitly included in the sample, like people who may not choose to participate. These questions also help anticipate the processes of social influence. If a person is surrounded by people who are planning to vote differently from them, that person might well be swayed by their friends by the time the election rolls around.

Social-circle questions also allow people to be more honest. "People can be embarrassed to admit if they plan to vote for a less-popular candidate, but they are less embarrassed to say it about their friends," says Galesic. And their answers enable scientists to learn more about the existence and size of echo chambers—groups of people who share the same opinions—among voters for different candidates.