Evidence based speech links to effectiveness of US Congress members
Epistemic orientation predicts legislative effectiveness among members of the US Congress
Computation and Language
Summary
Speaking with facts and evidence is important for making good decisions in government. The researchers looked at how much US Congress members use evidence-based language versus intuition-based language in speeches and tweets. They found that members who are more extreme in their political views tend to use less evidence-based language. Those who use more evidence-based language in their speeches are also more effective at passing laws. This suggests that focusing on evidence rather than intuition could help politicians work better.
epistemic orientationevidence based communicationUS Congresslegislative effectivenessideologyEvidence-Minus-Intuition (EMI) scorefloor speechesTwitterLegislative Effectiveness Score (LES)
Authors
Segun Aroyehun, Stephan Lewandowsky, David Garcia
Abstract
Truth and evidence-based communication provide important foundations for democratic governance, accountability, and collective decision-making. Prior work shows that evidence-oriented language in US congressional floor speeches has declined since the mid-1970s, alongside broader changes in legislative productivity and polarization. This study shifts the analysis from congressional sessions to individual members of Congress to examine whether epistemic orientation varies systematically across legislators and whether it relates to political behavior and legislative effectiveness. Using the Evidence-Minus-Intuition (EMI) score, we measure the relative prevalence of evidence-oriented versus intuition-oriented language in congressional floor speeches and Twitter posts. We link these measures to legislator-level data on ideology, institutional position, communication context, and Legislative Effectiveness Score (LES). The results show that more ideologically extreme members use less evidence-oriented language on the congressional floor. EMI also exhibits cross-platform consistency with members who use more evidence-oriented language in floor speeches also being more evidence-oriented on Twitter, although EMI is lower on Twitter overall. Finally, EMI in congressional speeches is positively associated with individual legislative effectiveness, even after accounting for ideology and extensive political, institutional, demographic, topical, and communication volume controls. These findings suggest that evidence-oriented language is not only an aggregate feature of congressional discourse but also a meaningful attribute of individual-level legislative communication and effectiveness.