About

Shanto Iyengar is the William Robertson Coe Professor and a Professor of Political Science and of Communication at Stanford University. He serves as the Director of the Political Communication Laboratory. Iyengar’s areas of expertise include the role of mass media in democratic societies, public opinion, and political psychology. His research has been supported by grants from prominent organizations such as the National Science Foundation, the National Institutes of Health, the Ford Foundation, the Pew Charitable Trusts, and the Hewlett Foundation. He has received several professional awards, including the Philip Converse Award of the American Political Science Association for the best book in the field of public opinion, the Murray Edelman Lifetime Achievement Award, and the Goldsmith Book Prize from Harvard University.

Research topics

• Political Science
• Sociology
• Law
• Social psychology
• Psychology
• Social Science
• Computer Science
• Media studies
• Advertising
• Gender studies
• Business
• Public relations
• Economics
• Cognitive psychology
• Philosophy
• Epistemology
• Microeconomics
• Internet privacy
• Demography
• Environmental ethics
• Developmental psychology

Selected publications

• Why are surveys struggling to estimate vote shares?

  American Journal of Political Science · 2026-04-28

  articleOpen access

  Abstract Polling in the 2020 US presidential elections significantly underestimated Trump support, calling into question the accuracy of all political surveys. Although many have speculated that this bias is due to Trump supporters refusing to respond to surveys, we have previously lacked the data to directly evaluate this theory. This paper leverages the rich and unique set of data collected alongside the 2020 American National Election Studies (ANES) to identify and quantify sources of error using the Total Survey Error framework. We document evidence of nonignorable unit nonresponse; that is, Trump supporters were less likely to respond and less likely to complete the 2020 ANES if they did respond. We are also able to rule out other potential sources of error. Our analyses identify a fundamental threat to political surveys, and careful diagnosis and quantification of the bias is critical for informing corrections and future survey design.

  PublisherDOI

• How deceptive online networks reached millions in the US 2020 elections

  Nature Human Behaviour · 2026-04-06

  article
  PublisherDOI

• No news is good news? The declining information value of broadcast news in America

  PLoS ONE · 2025-10-08

  articleOpen accessCorresponding

  Despite the rise of digital media, Americans are five times more likely to consume news via television than through online platforms. However, due in large part to technical hurdles, it remains unclear what content appears on broadcast news and how the mixture of content has changed over time. We consider these questions by applying a novel LLM-based approach to an understudied corpus of expert-generated summaries of virtually all news segments aired on the "big three" broadcast networks-ABC, CBS, and NBC-between 1969 and 2024. Results based on nearly one million news segments show that "information density"-the amount of time dedicated to political issues-has declined substantially over the last 50 years. Today, broadcast news spends roughly twice as much time on commercials and "soft" news and half as much on issue-based political coverage compared to a few decades ago. Since the early 1990s, the news has also shifted inward, focusing more on domestic stories and less on international affairs. These changes suggest a transformation in the informative role of broadcast news, raising questions about its impact on voter knowledge and political engagement.

  PublisherDOI

• Conceptualizing affective polarization

  Edward Elgar Publishing eBooks · 2025-07-08 · 19 citations

  book-chapter1st authorCorresponding
  PublisherDOI

• Identity Politics, Party Polarization, and the Rise of Donald Trump

  2025-01-01

  book-chapter1st authorCorresponding
  PublisherDOI

• No News Is Good News? The Declining Information Value of Broadcast News in America

  SSRN Electronic Journal · 2025-01-01

  preprintOpen access
  PublisherDOI

• The Diffusion and Reach of (Mis)Information on Facebook during the U.S. 2020 Election

  Sociological Science · 2024-01-01 · 25 citations

  articleOpen access

  Social media creates the possibility for rapid, viral spread of content, but how many posts actually reach millions? And is misinformation special in how it propagates? We answer these questions by analyzing the virality of and exposure to information on Facebook during the U.S. 2020 presidential election. We examine the diffusion trees of the approximately 1 B posts that were re-shared at least once by U.S.-based adults from July 1, 2020, to February 1, 2021. We differentiate misinformation from non-misinformation posts to show that (1) misinformation diffused more slowly, relying on a small number of active users that spread misinformation via long chains of peer-to-peer diffusion that reached millions; non-misinformation spread primarily through one-to-many affordances (mainly, Pages); (2) the relative importance of peer-to-peer spread for misinformation was likely due to an enforcement gap in content moderation policies designed to target mostly Pages and Groups; and (3) periods of aggressive content moderation proximate to the election coincide with dramatic drops in the spread and reach of misinformation and (to a lesser extent) political content.

  PublisherDOI

• Fear and Loathing in american politics: A review essay

  Revista Internacional de Sociología · 2024-12-30 · 2 citations

  reviewOpen access1st authorCorresponding

  President Donald Trump’s standing in the polls actually improved in the immediate aftermath of multiple criminal indictments. This development illustrates the phenomenon of affective polarization: intense conflict and ill will across the party divide, and intransigent political preferences that are entirely unresponsive to strong evidence. In this paper, I will provide a brief review of the evidence documenting the intensified state of affective polarization in America, identify possible underlying causes of this phenomenon, and offer some critical commentary on efforts to develop “treatments” that can ameliorate out-party animus.

  PublisherOA PDFDOI

• Persistent polarization: The unexpected durability of political animosity around US elections

  Science Advances · 2024-09-04 · 20 citations

  articleOpen access

  The scholarly literature suggests that, as elections approach, political tensions intensify, and, as they pass, tensions return to pre-election levels. Using a massive new dataset of 66,000 interviews (cross-sectional and panel), we find that animosities are durable and consistent over the course of the 2022 US election. Individuals with more exposure to the campaign tend to be more polarized, and this sentiment endures post-election. Contrary to expectations, partisans who voted for the winning candidate are no less polarized post-election than those on the losing side. In closing, we note that the durability of polarization has important implications not only for our understanding of the scope of partisan divides but also for efforts designed to ameliorate polarization.

  PublisherDOI

• Uncommon and nonpartisan: Antidemocratic attitudes in the American public

  Proceedings of the National Academy of Sciences · 2024-03-18 · 55 citations

  articleOpen access

  Democratic regimes flourish only when there is broad acceptance of an extensive set of norms and values. In the United States, fundamental democratic norms have recently come under threat from prominent Republican officials. We investigate whether this antidemocratic posture has spread from the elite level to rank-and-file partisans. Exploiting data from a massive repeated cross-sectional and panel survey ([Formula: see text] = 45,095 and 5,231 respectively), we find that overwhelming majorities of the public oppose violations of democratic norms, and virtually nobody supports partisan violence. This bipartisan consensus remains unchanged over time despite high levels of affective polarization and exposure to divisive elite rhetoric during the 2022 political campaign. Additionally, we find no evidence that elected officials' practice of election denialism encourages their constituents to express antidemocratic attitudes. Overall, these results suggest that the clear and present threat to American democracy comes from unilateral actions by political elites that stand in contrast to the views of their constituents. In closing, we consider the implications of the stark disconnect between the behavior of Republican elites and the attitudes of Republican voters.

  PublisherOA PDFDOI

Frequent coauthors

• Erik Peterson

  Rice University

  76 shared

• Kyu S. Hahn

  24 shared

• Tetsuro Kobayashi

  Waseda University

  20 shared

• Stephen Ansolabehere

  Harvard University

  20 shared

• Stuart Soroka

  20 shared

• Christian Collet

  16 shared

• Donald R. Kinder

  University of Michigan–Ann Arbor

  14 shared

• Donald P. Green

  Columbia University

  14 shared

Labs

• Political Communication LaboratoryPI

Awards & honors

• Philip Converse Award of the American Political Science Asso…
• Murray Edelman Lifetime Achievement Award
• Goldsmith Book Prize from Harvard University