Political lies have a pattern — and radical-right populist parties are leading the charge

A new study published in The International Journal of Press/Politics suggests that political misinformation on social media is not a widespread product of all ideological camps or populist movements, but is instead disproportionately linked to radical-right populist parties. The researchers, based at the University of Amsterdam and Vrije Universiteit Amsterdam, analyzed over 32 million tweets from parliamentarians in 26 countries over a six-year period and found that radical-right populists are significantly more likely to share misinformation than their mainstream or left-wing counterparts.

The study was motivated by a shift in the academic understanding of misinformation. While early work focused heavily on the viral spread of low-quality information on social media platforms, more recent attention has turned toward the role of political elites. Politicians, particularly those with large platforms and loyal followers, have the ability to influence public opinion and shape discourse—making their online behavior a critical area of study. Yet, until now, there was limited cross-national evidence connecting political ideology to the spread of misinformation by elected officials.

“Misinformation is one of the most widely researched societal phenomena of our era, and is often seen as a severe threat to societal and democratic institutions. Yet, the drivers of the rise in misinformation remain contested,” explained study author Petter Törnberg, an associate professor at the Institute for Logic, Language and Computation and co-author of Seeing like a Platform: An Inquiry into the Condition of Digital Modernity.

“My coauthor and I realized we had something to contribute here. She is comparative political scientist, and I’m a computational social scientist. By combining our two approaches, we could study misinformation through a novel lens: as a political phenomenon and expression of party politics.”

Törnberg and his co-author Juliana Chueri assembled a massive database containing tweets from 8,198 parliamentarians across 26 democracies, including countries like Germany, Canada, the United Kingdom, and the United States. The tweets, spanning from 2017 to 2022, included more than 18 million shared URLs. To identify misinformation, the team cross-referenced these links with two established databases: Media Bias/Fact Check and the Wikipedia Fake News list. These sources rate the factual reliability of media outlets on a scale from “very low” to “very high.”

From this, the researchers developed a “factuality score” for each political party, representing the average reliability of the sources their members shared. A low score indicated that a party’s members frequently shared links to unreliable or misleading sources. The team also gathered detailed information on each party’s ideological position using existing political science datasets, capturing whether a party leaned left or right, whether it embraced populist rhetoric, and whether it participated in government.

The central finding was that political ideology alone—or populism alone—did not predict whether a party would spread misinformation. Rather, it was the interaction of right-wing ideology and populist rhetoric that made a party more likely to share low-factuality content. Parties with high populism scores and a right-wing orientation were far more likely to disseminate misinformation than any other group. By contrast, left-wing populist parties and mainstream conservative or progressive parties did not show elevated levels of misinformation sharing.

While populism typically involves a distrust of elites and media, only its radical-right form was associated with low-factuality information sharing. Left-wing populists, who tend to focus on economic inequality and critique corporate power rather than cultural or national identity, did not engage in misinformation to the same extent.

“We were expecting misinformation to be linked to both left and right-wing populism. We however found that only radical right populism is predictive of misinformation spreading.”

This relationship held even after accounting for other factors like party cohesion, leadership style, and whether a party was in government or opposition. The study’s multilevel statistical models controlled for differences across countries, reinforcing the robustness of the findings.

One of the clearest illustrations came from the analysis of “party families” — political parties that share similar ideological foundations. Radical-right parties stood out with the lowest median factuality scores, significantly below those of socialist, green, liberal, and Christian democratic parties. Even when compared to other conservative parties, radical-right groups were far more likely to share links from sources known to publish misleading or false information.

The researchers argue that this pattern reflects the strategic use of misinformation as a political tool. Radical-right populists often seek to undermine trust in established institutions, including the media and the electoral system. By spreading misinformation, they can reinforce narratives of elite corruption, cultural threat, and institutional failure—ideas that are central to their political appeal. These tactics are especially effective in an attention-driven media environment, where provocative content is rewarded with engagement.

Importantly, the study emphasizes that this is not just a case of individual politicians behaving irresponsibly. Rather, it points to a structural alignment between radical-right populist ideology and the incentives of the digital media landscape. Misinformation becomes part of the broader political strategy, used to mobilize supporters, discredit opponents, and dominate media coverage.

“I think there’s a common understanding of misinformation as just an expression of our current media ecosystem: the quality of information is declining due to social media. Our study shows that this might not be the right way to think about misinformation. Instead, it appears to be a political phenomenon – linked to the rise of radical right populist politicians during the last decade, who are drawing on misinformation as a political strategy.”

Despite its scope and insights, the study is not without limitations. It only covers content shared on Twitter between 2017 and 2022, and future research will be needed to examine newer platforms and more recent trends. The analysis also focuses on shared URLs rather than the content of tweet texts themselves, potentially missing other forms of misinformation. Additionally, while the study included a diverse set of Western democracies, it does not provide insights into how misinformation operates in non-Western or authoritarian contexts.

Still, the findings open the door for a new approach to studying misinformation—not just as a media or technology problem, but as a phenomenon embedded in party politics. By making their data publicly available, the researchers hope to encourage future work that further explores the role of ideology, party strategy, and global political dynamics in the spread of false information.

Ultimately, this research reframes the conversation around misinformation. Rather than treating it as an unfortunate byproduct of social media, the findings suggest that misinformation is often a deliberate and calculated political tactic.

“We hope to establish a comparative approach to studying misinformation, in which we develop an understanding of misinformation as inextricably interlinked with political parties and movements. To address the caveats mentioned above, we are currently working on a larger-scale project, in which we study misinformation spread from virtually all the political parties in the world and use AI-techniques to identify misinformation and misleading information. We believe this will give us a much richer understanding of the global architecture of political misinformation.”

The study, “When Do Parties Lie? Misinformation and Radical-Right Populism Across 26 Countries,” was published January 13, 2025.