Political Communication Scholar Yphtach Lelkes Promoted to Full Professor

Yphtach Lelkes has always been curious about why people think and behave the way they do, especially when it comes to politics.

Lelkes, who was recently promoted to full professor at the Annenberg School for Communication at the University of Pennsylvania, studies the structure, dynamics, and causes of political attitudes, uncovering how psychology, media, and institutions shape political attitudes and polarization in the United States. He is now the Michael X. Delli Carpini Professor of Communication at Annenberg.

His research has explored how American legislators communicate, how people express partisan identities, and the impact of extreme language in public debate. He found that Democrats and Republicans vastly underestimate the diversity of each other’s views and that the majority of Americans do not support anti-democratic behavior, even when elected officials do.

“Yph’s research provides a crucial look into how people think about politics, providing the insight we need to lessen political division and strengthen democracy,” says Sarah Banet-Weiser, Dean of the Annenberg School for Communication. ”We are so lucky to have Yph as a colleague here at Annenberg; he is an exceptional scholar, a committed and compassionate teacher, and a wonderful department citizen. This is an incredibly well-deserved promotion.”

Lelkes didn’t grow up wanting to become a political scientist, but when the September 11 attacks happened during his first week of college, “politics suddenly became unavoidable,” he says. He initially majored in journalism, inspired by foreign correspondents covering the tumultuous political landscape, but switched his focus after being introduced to political communication as a subject of study. “Once I realized I could study how people think and talk about politics in a rigorous, empirical way, I decided to get my Ph.D. in Communication,” he says.

After receiving a master’s degree from Temple University and a Ph.D. from Stanford University, Lelkes taught at the University of Amsterdam, studying U.S. politics from afar. While it was fascinating to analyze American political culture from the Netherlands, he missed the academic community he had built in the United States.

When the opportunity to join the Annenberg faculty arose, he was thrilled. “What I love about Annenberg is that it’s a true ‘unicorn’ job: I have the freedom to study what I think matters, with great resources and a community that’s both rigorous and incredibly supportive,” he says. “I honestly didn’t know academia could feel this positive and stimulating until I got here.”

Lelkes is a prolific scholar — his research has appeared in top field journals in communication, psychology, and political science, including the Journal of Communication, the American Journal of Political Science, the Journal of Personality and Social Psychology, Proceedings of the National Academy of Sciences, and Nature Human Behavior — and he makes it a priority to include student researchers in his work.

“A lot of my work on polarization and political communication happens side by side with students: we’re building datasets, designing experiments, and arguing about what our theories really predict,” he says. “Their perspectives are essential for understanding how political attitudes and signals are changing, and that collaboration is one of the most rewarding parts of my job.”

Soon after arriving at Penn, he established the Democracy & Information Group (DIG), a working group that brought together graduate students interested in researching political communication. “I wanted a place where graduate students could bring their work, break bread, receive feedback, and practice rigorous but polite critical debate,” he says. “It was never a lab in the traditional sense, but a community where students learn how to do social science together.” Later, Lelkes and networks scholar Professor Sandra González-Bailón merged their respective working groups to create the Center for Information Networks and Democracy (CIND), a center that brings together researchers developing work at the intersection of political communication and computational social science.

Understanding Polarization

Much of Lelkes’s work focuses on affective polarization: the degree to which Democrats and Republicans dislike one another as groups. He first began studying the concept as a doctoral student at Stanford, under the guidance of mentors like political scientist Shanto Iyengar. In 2022, he co-founded the Polarization Research Lab with Iyengar and Sean Westwood, an associate professor at Dartmouth College, to better understand this phenomenon.

Since its launch, the lab has conducted weekly surveys tracking American attitudes toward partisan conflict, political violence, and democratic norms, and has made its datasets available free to scholars and members of the public. “The Polarization Research Lab is really about creating public resources,” Lelkes says. “It’s an opportunity to collect data and put it all out there for the world, so we can try to understand polarization: how important it is, what causes it, and what might actually fix it.”

Lelkes’s recent work focuses on political “signaling” — how people use partisan labels and hostile content online to declare who they are and which side they’re on. Last year, he received an Andrew Carnegie Fellowship to study signaling. His project reframes partisan animosity not as genuine hatred but as a strategic signal people use to navigate an increasingly chaotic information environment.

Lately, he’s been looking at how people signal partisanship online (for example, putting “MAGA” in a social media bio) and finds that those who feel most on the margins of their party are the ones most likely to engage in extreme signaling to prove they are loyal insiders, including sharing especially hostile political messages.

Making Connections

The thing Lelkes loves most about his career is the freedom to follow his curiosity — and to do so alongside scholars he admires and students who inspire him. His work at Annenberg gives him the opportunity to pursue questions wherever they lead, often by taking advantage of new forms of data and new ways of collecting it.

That might mean happening upon a database of evangelical sermons, building a custom app to study how people interact across group lines, or collecting and classifying nearly everything American politicians say in order to understand how political rhetoric works. As data have become more abundant and the tools for studying them more flexible, questions that once seemed impossible to answer have become research projects. For Lelkes, that ability to turn curiosity into evidence — and evidence into a better understanding of politics, public opinion, and social behavior — is one of the most exciting parts of the job.

At the same time, he draws inspiration from the classes he teaches and conversations he has in the hallways at Penn: “My favorite classes are the ones where I’m not just standing up there imparting wisdom; we’re creating understanding together so everyone leaves thinking about the world a little differently — including me.”