Scientific Expertise in Citizen Assemblies: A Systematic Literature Review of Roles, Tensions, and Democratic Implications

Citizen assemblies have gained prominence as a tool for participatory governance, providing citizens with a structured space to deliberate on complex public policy issues. Central to their effectiveness is the integration of scientific expertise, which informs participants and helps bridge knowledge gaps on technical topics such as climate change, healthcare policy, and constitutional reform. However, the reliance on expert knowledge raises significant questions about power dynamics, legitimacy, and the democratic values underpinning deliberative processes. This paper presents a systematic literature review of academic research on the role of scientific expertise in citizen assemblies, examining the extent to which it supports or constrains inclusive and effective deliberation and decision-making. The review synthesizes findings from over two decades of research, focusing on peer-reviewed studies that explore the epistemic dimensions of deliberative democracy. Key themes emerging from the literature include: (1) the epistemic benefits of expert input in enhancing decision-making quality; (2) the potential for expert dominance to undermine participant agency; (3) the role of transparency in expert selection and evidence presentation; and (4) innovations in facilitation, such as the use of “epistemic brokers” to mediate between scientific and lay perspectives. The review also identifies gaps in the literature, such as the need for comparative studies across different political and cultural contexts. Our findings suggest that while scientific expertise is crucial for addressing complex issues, its incorporation must be carefully managed to avoid creating hierarchies that marginalize citizen voices. Effective citizen assemblies balance expert input with participatory deliberation by fostering epistemic humility and ensuring that participants have opportunities to challenge and contextualize expert advice. By systematically mapping the current state of research, this paper contributes to the growing body of knowledge on deliberative democracy and epistemic justice. It provides practical recommendations for designing citizen assemblies that uphold democratic principles while benefiting from scientific expertise. This review highlights the importance of transparent, inclusive, and reflexive processes that empower citizens to engage meaningfully in policy deliberation, rather than becoming passive recipients of expert knowledge. This work aims to inform scholars, facilitators, and policymakers on how to design evidence-informed, yet democratically robust, citizen assemblies capable of navigating contemporary governance challenges.