Changing people's minds requires evidence—not just guesswork

Despite multimillion dollar advertising campaigns and debates in which political candidates express their views for free, just a small number of people—5 to 7 percent—ever end up changing their minds about those running for office.

That means high-costing advertising campaigns are really just targeting “this tiny, tiny percentage,” says Penn political scientist Diana Mutz.

The same holds true for many issues that are highly partisan—including gun control.

“It’s a lot harder than you think. People are used to the idea you can change anybody’s mind with a 30-second ad,” says Mutz, the Samuel A. Stouffer Professor of Political Science and Communication with appointments in the Annenberg School for Communication and the School of Arts & Sciences. “The American public has always been much harder to persuade.”

This was the challenge she presented to the undergraduates enrolled in her fall course, “Media and Politics.” After a semester exploring the media’s influence on politics, Mutz asked her class to persuade people to reexamine their views.

Students were grouped in teams of two and told to create a 30-second advertisement around an issue. The class decided to address gun control rather than other hot-button issues like immigration.

The students used the iPOLL database, which contains all publicly released opinion polls, to research public opinion on gun control over time.

Students focused on persuading pro-gun conservatives to adopt more gun control measures, says Dia Sotiropoulou, a junior in the College of Arts & Sciences, adding this is an especially difficult group to budge.

“In campaigns, a great deal of the advertising that’s produced, a lot of the campaign strategies, are not based on research,” explains Sotiropoulou. “A lot of this is based on gut logic. ... It’s a bit shocking because candidates pour millions and millions of dollars into their media.”

In Sotiropoulou’s ad, which she worked on with College junior Jackie Dworkin, footage of a positive experience from a young woman’s first deer hunt is followed by harrowing black-and-white images from the Columbine High School shootings.

Other classmates took different approaches. One, created by College seniors Molly Rooney and Ariela Boillat, referenced the Sandy Hook shootings of 2012. Senior Alex Metzman and junior Max Levy created an ad with animation with a voiceover from a gun owner advocating for background checks. And in the ad created by junior Zach Fox and senior Spencer Winson, they film someone in a shop easily purchasing a gun.

After presenting background for their ads and screening them for the class, students voted on which they thought would be the most effective.

Mutz then hired a polling firm to test the videos on a national online sample of respondents and found that just three of the eight videos produced a statistically significant response—ads from Fox and Winson, Rooney and Boillat, and juniors Lauren Feiner and Paola Ruano that depicted the tragic unintended consequences behind concealed carry of a gun.

Before the polling, the students thought the animated video from Metzman and Levy would be the most effective.

“We can’t intuit these things,” says Sotiropoulou. “What our own guts tell us can often radically misalign with what the [research] tells us.”

Mutz says the point of the exercise was to show students that political consultants need evidence to change people’s views.

“First, getting people’s attention to a message [is] really difficult to do and sometimes outrageous ads or clever ads get people’s attention, but they don’t necessarily process the message,” Mutz says. “It’s really a difficult thing to shift people’s viewpoints. If you’re going to spend money on it, it’s really important to do research.”

Sotiropoulou says the class debunked many perceptions about how the media and politics interact, and underscored the disparity between how the public perceives the media and the role the media imagines it has in changing people’s minds.

Mutz hopes her students will put their critical-thinking research skills to work in the future.

“Regardless what kind of job they seek in the future, knowing how to do this ... [is] just tremendously valuable, no matter what kind of job you’re in,” Mutz says. “Evidence-based everything is becoming more important.”

To watch the student videos, go to

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