Showing sympathetic figures with differing beliefs, discussed over a drink. Highlighting a shared identity. Correcting misperceptions about opposing partisans’ views on democracy.

Those are a few of the most effective strategies for reducing political polarization in the U.S., identified by a “megastudy” that surveyed more than 32,000 Democrats and Republicans to test 25 ideas crowdsourced from social scientists and other experts around the world.

Led by an incoming Cornell faculty member, the research highlights opportunities to ease tensions that the current election cycle could exacerbate – if successful strategies can be implemented consistently and at scale.

“There are a lot of actors that have a vested interest in reducing polarization and strengthening democratic attitudes in the U.S.,” said Jan Voelkel, a postdoctoral associate and incoming assistant professor of public policy and sociology in the Cornell Jeb E. Brooks School of Public Policy. “We provide insights into what kind of psychological mechanisms they would need to trigger if they were to launch scalable interventions.”

Voelkel is the first of more than 80 co-authors of “Megastudy Testing 25 Treatments to Reduce Anti-democratic Attitudes and Partisan Animosity,” published Oct. 17 in Science. The research was conducted as part of the Strengthening Democracy Challenge at Stanford University, where Voelkel earned his doctoral degree.

Although polarization is studied widely, Voelkel said, differing methods have made comparing strategies for reducing it a challenge. The new study sought to rectify that issue and – in the wake of unfounded election fraud claims and the Capitol attack on Jan. 6, 2021 – to make rapid progress, by putting as many ideas as possible to a head-to-head test with the same sampling population, outcomes and control condition.

The scholars issued an open call to academics and professionals (e.g., think tanks, nonprofits, journalists) for ideas on how to reduce partisan animosity and support for anti-democratic attitudes and political violence. Proposals poured in: 252 from 419 people based in 17 countries on four continents – indicative, Voelkel said, of U.S. democracy’s importance to the world. An advisory panel helped select the most promising 25 submissions, the most funding allowed.

Study participants were Democrats and Republicans, matching quotas consistent with high-quality samples for demographic factors including gender, age, race, ethnicity, education, strength of partisan identification, and region. They were randomly assigned to control groups or survey treatments, which were conducted online and took up to eight minutes.

Regarding partisan animosity, the results were encouraging: 23 of 25 tested ideas reduced it significantly. The strategies underlying the treatments with the largest effects were:

• Highlight relatable, sympathetic people with different political beliefs. The most successful example showed a British Heineken ad, “Worlds Apart,” that brought together pairs of strangers with differing beliefs about feminism, climate change and transgender rights, showing each pair bond, then continue talking over a beer.
• Highlight common cross-partisan identity. One effective treatment suggested most Democrats and Republicans constitute an exhausted majority tired of polarization. Another argued partisans are united by their American identity.

“We have a pretty good understanding of how to reduce basic dislike of opposing partisans,” Voelkel said, “and the effects were quite sizable, so we thought that was great news.”

How to reduce anti-democratic practices is less understood; only six survey treatments accomplished that significantly. The most successful strategies were:

• Highlight exaggerated stereotypes about the other side. Data shows partisans’ actual support for undemocratic practices is far less than opponents think.
• Highlight democracy’s importance: A treatment including a video showing footage from countries where democracy has collapsed and from the Jan. 6 riot made the case that the U.S. also is vulnerable.
• Show elites endorsing democratic norms. One example is a 2020 ad, “One Nation,” in which Utah’s candidates for governor agree to respect the election’s outcome.

“We still have a lot to learn about anti-democratic attitudes, but we have some intriguing findings that we can build on,” Voelkel said. “Our research shows that it is in principle possible to reduce these concerning attitudes.”

The megastudy also suggested the importance of assessing the strategies' effects on multiple outcomes. For example, while highlighting the threat of democratic collapse reduced support for undemocratic attitudes among both Democrats and Republicans – although working better for Democrats than Republicans – it also had a backfire effect. The video increased support for political violence among the most conservative Republicans, presumably because they fail to view Jan. 6 as an undemocratic action.

Following up with nearly 9,000 study participants two weeks later, the researchers found the depolarizing effects had waned significantly. That suggests even the most effective strategies would need to be executed often or with greater intensity. Promising applications may include social media platforms adjusting algorithms to promote common instead of extreme voices; the broader media landscape exposing people to more pro-democratic messages; and political elites promoting democratic values and institutions.

“There are effective ways to reduce polarization, but we need systemic interventions to really have a sustainable impact,” Voelkel said. “Dozens of scientists collaborated on this study. Now we also need large-scale collaborations to put the findings into action.”

In addition to Voelkel, junior scholars leading the megastudy are Nick Stagnaro, postdoctoral researcher at the Massachusetts Institute of Technology, and James Chu, assistant professor of sociology at Columbia University. Lead senior authors are Robb Willer, director of the Polarization and Social Change Lab and co-director of the Center on Philanthropy and Civil Society at Stanford; David Rand, director of the Applied Cooperation Initiative at MIT; and James Druckman, political science professor at the University of Rochester.

The research was supported by the Stanford Center on Philanthropy and Civil Society, the Stanford Impact Lab, the Civic Health Project and the Fetzer Institute.