Persuasion expert Robert Cialdini
From an article in Grist.org
I can give you some evidence of what happened in the presidential campaign, where the Democratic National Committee used this information in very effective ways to get out the vote. They recognized that it was a serious mistake to do what they had been doing in previous elections, saying to registered Democrats, “So many Democrats failed to vote in 2004 that it caused this terrible country.” Instead, they changed the wording to, “So many Democrats voted. Join them!” There’s a recent article in the Journal of Politics that showed that those two strategies had dramatically different effects on voting behavior.
Notice what the Obama campaign did when it announced the donations it had received the previous quarter. It was brilliant: they didn’t just list the amount of money they had received, they listed the number of contributors who had donated. The multitude became the message. People want to be with the crowd. It tells them something not only about what’s appropriate, but what’s possible for them.
If we send people in San Diego a message saying the majority of your neighbors are conserving energy on a daily basis, that has more effect than telling them to do it for the environment or to be socially responsible citizens or to save money. If your neighbors are doing it, it means it’s feasible. It’s practicable. You can do it — people like you.
It was very important that we say “people in your neighborhood.” If we said “the majority of Americans,” that wasn’t effective. If we said “the majority of Californians,” that was more effective. If we said “the majority of San Diegans,” that was more effective. But the most effective was “the majority of your neighbors.” That’s how you decide what’s possible for you: what people in your circumstance are able to do.