Stephan Lewandowsky, University of Bristol
Abstract:
The spread of online misinformation in social media is increasingly perceived as a problem for societal cohesion and democracy. The role of political leaders has attracted less research attention, even though politicians who “speak their mind” are perceived by segments of the public as authentic and honest even if their statements are unsupported by evidence or facts. Analyzing communications by members of the U.S. Congress on Twitter between 2011 and 2022, we show that politicians’ conception of truth has undergone a distinct shift, with authentic but evidence-free belief-speaking becoming more prominent and more differentiated from evidence-based truth-seeking. For Republicans-but not Democrats-an increase of belief-speaking of 10% is associated with a decrease of 12.8 points of quality (using the NewsGuard scoring system) in the sources shared in a tweet. An increase in truth-seeking language is associated with an increase in the quality of sources for both parties. We also show that the conception of truth expressed by politicians sets the tone of the ensuing conversation with members of the public on Twitter. The results support the hypothesis that the current dissemination of misinformation in political discourse is in part driven by a new understanding of truth and honesty that has replaced reliance on evidence with the invocation of subjective belief.