Christopher Bryan, Gregory Walton, Todd Rogers, and Carol Dweck did two experiments in which they increased people’s voter turnout in real electionsby over 10 percentage points by simply asking them the following survey question on election day:
How important is it to you to be a voter in the upcoming election?
In the comparison condition, potential voters were asked:
How important is it to you to vote in the upcoming election?
Unfortunately, there doesn’t seem to have been a control condition in the experiments, so all they could really do was compare these two treatments to each other.
The gimmick of the experiment is that it harnesses humans’ natural belief in essentialism (see, for example, reference 14 in the link above), the idea that being “a voter” is more essential than being a person who happened to vote.
As Bryan et al. put it, “people may be more likely to vote when voting is represented as an expression of self—as symbolic of a person’s fundamental character—rather than as simply a behavior.”
This all makes sense. What about the estimated effect size of 10-14 percentage points? That sounds implausibly huge: given all the campaigning that goes on, could a single survey question really have that large an effect? I can’t believe it. Well, maybe. The key is that the experiment was done on election day itself (or the day immediately before). I suppose if somebody catches you just at the right time, it can make a big difference.