Konstantinos Papaioannou is an Assistant Professor of Political Behaviour at the Department of Political Science and International Relations, University of the Peloponnese. His research interests lie in the fields of political psychology and political behaviour, with a particular focus on the formation of citizens’ political attitudes, the functioning of democracy, and the relationship between citizens and political institutions and parties. His work has been published in leading international academic journals, including Political Psychology, British Journal of Social Psychology, International Political Science Review, British Journal of Psychology, European Journal of Social Psychology, and Acta Politica, among others. He has taught and worked at universities across Europe, including the London School of Economics (UK), Utrecht University (the Netherlands), the Université libre de Bruxelles (Belgium), and Lund University (Sweden), as well as in the United States (University of California, Berkeley).

He is the Principal Investigator of the research project “The Age of Post-Truth: Political Parties and Conspiracy Theories” (Hellenic Foundation for Research and Innovation – HFRI, 2026–2028), which is implemented at the Department of Political Science of the Aristotle University of Thessaloniki, where he was awarded his PhD in Political Science. This project builds on his doctoral dissertation (“An Arena of Angry Minds? Uncovering Hidden Relationships: Conspiracy Theories, Populism and Democracy”) and examines conspiracy theories and populism in political discourse, drawing on data from social media platforms (Facebook, Instagram, X/Twitter) through a comparative analysis of European countries.

He has worked for several years as a Senior Researcher at the National Centre for Social Research (London, UK), where he led and contributed to research projects funded by the UK government on public attitudes and politics in post-Brexit Britain. These projects also involved the evaluation of public policy programmes and interventions using experimental and quasi-experimental methods, contributing to evidence-based public policy decision-making (e.g. British Social Attitudes).

He is also the elected Chair of the Early Career Committee of the International Society of Political Psychology (ISPP).

Political Psychology, Political Behaviour, Experimental Research Designs, Democracy and Political Attitudes, Populism, Political Communication and Social Media

1. Papaioannou, K., Slewe, S., Pantazi, M., & van Prooijen, J. W. (2025). “Dissatisfied democrats, but democrats nonetheless?” Unravelling the democratic paradox between populism and preference for alternative political systems. Political Psychology.
2. Papaioannou, K. & Pantazi, M. (2025). “Please Reduce the Gap! How Psychological Distance to Politics Fuels Belief in Conspiracy Theories”. British Journal of Social Psychology.
3. Papaioannou, K., Pantazi, M., & van Prooijen, J. W. (2025). The ‘sour grapes’ of conspiracy theories: how does the emotion of ressentiment predict conspiracy beliefs? Acta Politica, 1-27.
4. Papaioannou, K. (2025). ‘Sour grapes and the seeds of discontent’: Citizens in ressentiment and the populist surge. International Political Science Review, 01925121241309925.
5. Papaioannou, K., Pantazi, M., & van Prooijen, J. W. (2024). Rejection of the status quo: Conspiracy theories and preference for alternative political systems. British Journal of Social Psychology, 63(4), 2077-2099.
6. Papaioannou, K., Pantazi M. & van Prooijen, J. W. (2023b), Is Democracy under Threat? Why Belief in Conspiracy Theories predicts Autocratic Attitudes. European Journal of Social Psychology, 53(5), 846-856
7. Papaioannou, K., Pantazi, M., & van Prooijen, J. W. (2023a). Unravelling the relationship between populism and belief in conspiracy theories: The role of cynicism, powerlessness and zero‐sum thinking. British Journal of Psychology, 114(1), 159-175
8. Pantazi, M., Papaioannou, K., & van Prooijen, J. W. (2022). Power to the people: The hidden link between support for direct democracy and belief in conspiracy theories. Political Psychology, 43(3), 529-548.