Josh Kalla ’09: Researching Politics, Persuasion and Prejudice

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Josh Kalla ’09: Researching Politics, Persuasion and Prejudice

When Dr. Josh Kalla went knocking on doors to ask strangers about hot-button political issues, he wasn’t looking for an argument. He just wanted to engage in a civil, face-to-face conversation – and in the process, gather data for his political science research.

Kalla would start by asking people how strongly they agreed or disagreed with a statement about civil rights protections for a particular marginalized group. If the person indicated discomfort with or a prejudiced opinion of the group, he would listen respectfully. Then, rather than shaming or shouting at them, he would share a story and photo of a friend who belongs to that group.

“You don’t want people to dig in their heels and double down on whatever position they’re originally holding,” said Kalla, an assistant professor of political science and data science at Yale University. Instead of slammed doors or expletives, this field experiment led to real data on what kinds of conversations are the most effective at reducing prejudice.

Kalla specializes in using data and randomized field experiments to research political persuasion, voter decision making and prejudice reduction. For the political science professor, it’s an endlessly fascinating field of study because it touches on so many facets of daily life.

“It matters for the world of politics, but it also matters for people’s social dynamics. Are people feeling safe and comfortable in school? In the workplace?”

His academic studies on political behavior rely on the same rigorous methods used in clinical drug trials.

He has worked with political campaigns and nonprofits to conduct field research to help them determine factors that make people change their minds – whether that is to vote for a particular candidate or view a marginalized group with less suspicion or hostility. 

Josh Kalla '09

“They do the actual campaign work, but I do the data work and analysis,” he said.

For example, in the prejudice reduction research he devised for nonprofit groups, some canvassers are assigned to start conversations with homeowners about a marginalized group such as transgender people or undocumented immigrants. Other homeowners receive the equivalent of a placebo – a reminder to recycle or a quick survey about news consumption.

Follow-up surveys showed that people who had the face-to-face prejudice reduction conversations had less negative impressions of the marginalized group. Over the course of several thousand door knocks, the research helped to pinpoint what types of conversations were more successful at reducing prejudice and why.

Kalla believes this type of nonjudgmental approach works because it is extremely difficult for a person to admit they are wrong and modify their opinion. “You can make it a little easier being nonjudgmental and being curious and creating a comfortable space.”

Though social media spats might give the impression that bigotry is on the rise, Kalla said broad national surveys show that overt prejudice has been decreasing. “Americans might hold racist, sexist and transphobic views, but prejudice and prejudicial views evolve and become less socially comfortable over time.”

David Broockman, an associate professor of political science at the University of California-Berkeley, has collaborated with Kalla on the prejudice reduction research and numerous other studies that have been published in academic journals and featured in major national media outlets.

Broockman said Kalla excels at academic research because of his strong sense of integrity. He said researchers in academia have to make a case for their study in a published paper, and sometimes without even realizing it, or without any bad intent, they might skew the data or look at it in a certain way to highlight the desired result.

“There are ways that academics cannot be fully transparent or honest about the data they have,” said Broockman. “But at every turn, Josh is thinking about how we can do this research in such a way that we are not going to fool ourselves and present it in the most transparent way possible. I have never met anyone that has the same kind of fierce dedication to research integrity as Josh.”


Kalla, who grew up in Squirrel Hill, was always fascinated by politics. He figured he would  become a lawyer like his grandfather, sometimes accompanying him to the courtroom.

He transferred to Shady Side Academy in high school, and through his English and history classes, such as the one taught by Matt Weiss, learned the valuable skill of writing a research paper. “I still use those skills today when I am doing social science research.”

He also was a skilled debater. “He took me under his wing on the debate team,” said Frankie Costa ’10, who was a year behind Kalla at both Shady Side and Yale University.

“He was always very thoughtful, conscientious and compassionate. There were some folks who were more theatrical in debate, but he was always very level-headed. You couldn’t fluster him. He always instinctively seeks the truth,” whether in a debate tournament or his academic career.

Kalla entered Yale in 2009, and in the spring of his freshman year, he took a political science  course that introduced him to field experiments and data analysis. Kalla, who went on to earn

both a bachelor’s and master’s degree in political science at Yale, was hooked on this kind of social science research.

He continued his research at the University of California-Berkeley, where he received a second master’s degree and a Ph.D. in political science. Upon graduation, he worked at the Analyst Institute in Washington, D.C., designing and analyzing field studies on how voter contact strategies affected political behavior.

He joined the faculty of Yale in 2019, the same year he got married. He met his husband, Armon Dadgar, through Broockman.

The COVID-19 pandemic afforded many opportunities to observe politics during an era of expensive and protracted campaigns, both during the 2020 presidential election and the 2022 midterm elections.

Anyone who watched TV, opened their mail or answered their doors during those campaigns – particularly in a swing state like Pennsylvania – was bombarded with literature and ads. But does this barrage of political ads actually persuade people? Not really, Kalla’s research showed.

“What campaigns are doing is almost canceling each other out,” Kalla said. “The additional piece of mail or TV ad really isn’t doing much. American elections are fairly balanced. There’s some money disparity, but each side tends to spend a lot of money.”

What does appear to sway likely Republicans or likely Democrats, however, is a nudge to go to the polls and vote.

“Even people who don’t vote view it as important, but often they need a little bit of extra knowledge. So if you tell them where to vote, when to vote, that information can be very effective for getting them over the hump.”

Kalla also has conducted research on the media’s role in changing views in today’s polarized political landscape.

It’s often said that partisans are in their own bubbles or political silos – viewers of Fox News watch one version of reality while viewers of CNN or MSNBC see something entirely different. Kalla wanted to find out if it was possible to change those entrenched views by creating an artificial construct. Would attitudes change if you paid loyal viewers of one cable network to watch a different one?

He and Broockman conducted an experiment in September 2020, in the wake of George Floyd’s death and when the COVID-19 pandemic was raging. While Fox News was covering property damage during the protests following Floyd’s death, CNN was reporting on pandemic deaths and criticisms of President Donald Trump’s handling of the crisis.

Fox News viewers were paid $15 an hour to watch CNN for six hours a week over four weeks. The conventional wisdom of the media and academics said it wouldn’t make any difference, because people in their partisan silos are set in their views. “By this point, Trump had been calling CNN ‘fake news’ for four-plus years,” Kalla said.

But the research showed the Fox viewers’ opinions were changed by watching some segments of CNN for one month. They started to take COVID-19 more seriously and were more critical of Trump’s handling of it, the research showed.

Though Kalla did not secure funding to do the reverse – pay CNN voters to watch Fox News – he believes the same phenomenon would have occurred: CNN viewers would likely have been less critical of Trump, he predicted.

“The encouraging finding is that even though these people were really strong partisans, consistent ideologues, they were still open to learning new information,” he said. 

Josh Kalla '09

Kalla, who was awarded Yale’s Arthur Greer Memorial Prize for Outstanding Scholarly Publication or Research in 2022, is also a resident faculty fellow at Yale’s Institution for Social and Policy Studies. In his classes, he teaches students to conduct field experiments and analyze research data.

In his Data Science for Political Campaigns class, students learn how data drives so many political decisions – where a campaign competes, the type of messaging, the voters targeted. In the course Measuring Impact and Opinion Change, his students learn how political campaigns, marketers, nonprofits and other organizations try to sway opinions through advertising and door-to-door canvassing. Kalla teaches them how to measure change and “how to be appropriately skeptical of findings that claim to measure impact.”

For a final project, students conduct their own randomized field experiment. Last year, a group of students partnered with a garden center to measure the impact of advertising a price ending in $.99 versus a price rounded up to the largest whole dollar.

“They ended up finding that the pricing of $.99 vs. the nearest whole number didn’t matter,” he said. “But this is a nice example of how students come up with their own research question, implement their own experiment, and then gather and analyze data.”

His former students have gone on to law school and Ph.D. programs in political science. They also have landed jobs in government, political campaigns and as journalists. One of his former students who worked on a labor union campaign came to his class recently to talk about his experiences.

Kalla said he always gains new perspectives through teaching. “Every time I teach a course, students come with new ideas or new questions. It keeps things exciting.”