Berger and fellow author Marc Meredith of Stanford University’s Graduate School of Business recognized that there are other potential factors that might drive such a difference and engaged in additional analysis of the data that showed this wasn’t the case. They also created a controlled test that took the whole bias question out of the equation.
They gave people different images and asked them to rate how bright the images were. Berger says that wasn’t what they were really interested in-- they were instead interested in the “content of those images” because some people were exposed to many more school images than the others got.
Berger says, “Then, in the context of an unrelated study, we asked them to cast votes on a number of initiatives, including the… initiative from Arizona.” What they found, says Berger, was that just seeing the school-related images “increased the chance that people said they would support an education funding initiative.”
Berger cautions that this research does not show that where you vote can change a decision you’ve already made, emphasizing that this impacts people “who aren’t sure, who are on the margin.”
He illustrates this with a moment when space exploration influenced candy bar sales. He says when NASA landed twin rovers on Mars and it was in the news, “people were choosing Mars bars over other types of candy bars.” Again, people with specific preferences wouldn’t be affected, but for the “many people (who) may be indifferent…then the cues in the environment could have a much larger effect.”
The researchers are not suggesting that schools be abandoned as polling sites -- because all buildings will have cues that unconsciously impact voters -- but that people take steps to look for these cues and try to minimize their impact.
Berger says future research is needed to determine whether this extends to other types of ballot measures, including candidates.
This research was published by the Proceedings of the National Academy of Sciences Online Early Edition for the week of June 23, 2008 and was funded by The Stanford Graduate School of Business.