The ongoing discourse around “alternative facts” has a complicated and troubling history in US politics. Historically, the battleground of political debate has often revolved around the struggle between objective realities and subjective interpretations. A recent study led by a team of researchers from the Cluster of Excellence “The Politics of Inequality” takes an in-depth look into the evolution of political rhetoric within the US Congress over the past 140 years. This comprehensive analysis scrutinizes an astounding eight million congressional speeches from 1879 through 2022, with the aim of understanding whether lawmakers primarily rely on empirical data or lean more towards personal beliefs and interpretations.
The researchers discovered a profound and worrying trend: since the 1970s, the reliance on evidence-based rhetoric among members of Congress has been diminishing significantly, reaching a record low in contemporary times. This decline in fact-centric language correlates with other disheartening trends: a drop in legislative productivity, skyrocketing political polarization across party lines, and a growing sense of economic disparity within the American landscape. The insights gleaned from this extensive study provide a sobering glimpse into the current state of political discourse.
David Garcia, the lead author and a professor of social and behavioral data science at the University of Konstanz, emphasizes that this issue is not confined to the borders of the United States. Around the globe, democracies are wrestling with what is often termed “truth decay.” This phenomenon is characterized by an increasingly blurred line between fact and opinion, which further exacerbates societal polarization and erodes public trust in key institutions. The research team’s examination into congressional rhetoric serves not only as an academic exploration but also as a warning sign regarding the health of democratic dialogue in the modern era.
The analysis reveals that effective democratic exchanges should ideally strike a balance between evidence-based discussions and intuition-driven arguments. While facts serve as an essential foundation for reasoned debate, personal beliefs enrich the conversation, infusing it with emotional and experiential dimensions crucial for addressing societal problems. An imbalance—where subjective opinions take precedence over factual analysis—poses a significant threat to the integrity of political discourse, a trend starkly evident in the evolving nature of congressional speeches.
From the late 1800s to the mid-20th century, the relationship between fact-based and intuition-based rhetoric remained relatively stable. However, after 1940, the scales began to tip toward a predominance of factual arguments, peaking in the mid-1970s. This reliance on empirical evidence has been on a steep decline since 1976, diminishing considerably up to the present day. The findings are disquieting as both Republican and Democratic speakers have experienced this downturn, though the trend appears to be more pronounced within the Republican Party since 2021. Interestingly, this erosion of fact-based dialogue is not confined merely to formal speeches; a similar pattern emerges in the analysis of Twitter posts made by members of Congress, further confirming this disturbing trend.
Another notable dimension of the research indicates a compelling relationship between the quality of congressional discourse and legislative effectiveness. Professor Stephan Lewandowsky, co-author of the study and Chair in Cognitive Psychology at the University of Bristol, points out that a higher frequency of evidence-based language correlates with enhanced performance in Congress. As reliance on empirical evidence diminishes, so too does legislative efficiency and cross-party cooperation. The implications of these findings urge a reconsideration of how language is wielded by politicians within legislative venues.
The methods employed in this study reflect a groundbreaking approach to data analysis in political rhetoric. The research team utilized advanced computational techniques to extract long-term trends concerning the language utilized by US Congress members. This extensive analysis harnesses the power of text analysis methodologies, capturing the dynamic interplay of language over a period that spans nearly a century and a half.
To begin their study, the researchers identified distinctive keywords that signified either fact-based or intuition-driven language. Terms associated with objective discussions include “analyze,” “data,” “findings,” and “investigation,” while words such as “point of view,” “common sense,” “guess,” and “believe” represent subjective rhetoric. By calculating the ratio of these categories in congressional speeches, the team developed the Evidence-Minus-Intuition (EMI) index, allowing for a nuanced representation of rhetorical focus. A positive EMI score indicates an emphasis on factual communication, while a negative score reflects a dominance of personal opinions.
These quantitative insights are grounded in a comprehensive historical framework. The focus on language shifts over time reveals not just the rhetorical strategies employed, but also illuminates broader societal changes impacting political discourse. In a world increasingly dominated by digital communication, such transformations in language can shape public perceptions and, subsequently, democratic engagement.
Jana Lasser, a data analysis professor at the University of Graz, echoes the significance of the findings. In her previous work analyzing Twitter posts by members of Congress, she observed similar trends indicating a gradual shift toward prioritizing personal belief systems over scientific data. This pattern further underscores the importance of scrutinizing how political dialogue is framed and understood, particularly in an age when social media plays an outsized role in shaping public discourse.
As the study concludes, it raises critical questions about the future of political communication within the US and beyond. The editorial illustrates the pressing need for efforts directed toward reviving evidence-based discourse in politics. By fostering a culture that prioritizes facts and objective analysis, the democratic process can be reinvigorated, potentially restoring public confidence in political institutions.
In this light, the findings of Garcia and his collaborators serve not merely as an academic reflection but as a call to action. Institutions, lawmakers, and citizens alike must recognize the profound implications of rhetoric on policymaking and democratic engagement. It is through such consciousness that a more informed and productive political dialogue may emerge, one where the equilibrium between facts and intuition is restored and cherished.
The narrative painted by this extensive study is not so much an account of the failures of political language as it is a testament to the potential revolutionary changes in democratic discourse that could arise. By understanding the value of balanced rhetoric rooted in both factual integrity and personal conviction, society can pave a path toward a more enlightened and effective governance.
As the conversation around political rhetoric continues, the insights provided by this research starkly highlight the importance of engaging with language thoughtfully and critically. In striving for a political culture that values empirical evidence over conjecture, the foundations of democracy can be strengthened, ensuring that the voices of the people remain anchored in a shared reality.
This research underlines a salient truth about political engagement: it is the nature of discourse that shapes not just public opinion, but also the very essence of democratic principles. In recognizing and acting upon this truth, the future of political dialogue can be redefined, echoing a commitment to reasoned debate that genuinely reflects the complexities of the societies in which we live.
Subject of Research: Political rhetoric and the evolution of evidence-based versus intuition-based discourse in the US Congress
Article Title: Computational analysis of US Congressional speeches reveals a shift from evidence to intuition
News Publication Date: April 10, 2025
Web References: Nature Human Behaviour, DOI: 10.1038/s41562-025-02136-2
References: Aroyehun, Segun et al., “Computational analysis of US Congressional speeches reveals a shift from evidence to intuition,” Nature Human Behavior.
Image Credits: Ines Janas; Segun Aroyehun; Jana Lasser; Stephan Lewandowsky
Keywords: Political rhetoric, Evidence-based discourse, Intuition-based discourse, Congressional speeches, Political polarization, Data analysis, Democracy, Social discourse, Language evolution, Truth decay.
