Too Polite to Disagree: Understanding Sycophancy Propagation in Multi-Agent Systems

Vira Kasprova, Amruta Parulekar, Abdulrahman AlRabah, Krishna Agaram, Ritwik Garg, Sagar Jha, Nimet Beyza Bozdag, Dilek Hakkani-Tur


Abstract
Large language models (LLMs) often exhibit sycophancy: agreement with user stance even when it conflicts with the model’s opinion. While prior work has mostly studied this in single-agent settings, it remains underexplored in collaborative multi-agent systems. We ask whether awareness of other agents’ sycophancy levels influences discussion outcomes. To investigate this, we run controlled experiments with six open-source LLMs, providing agents with peer sycophancy rankings that estimate each peer’s tendency toward sycophancy. These rankings are based on scores calculated using various static (pre-discussion) and dynamic (online) strategies. We find that providing sycophancy priors reduces the influence of sycophancy-prone peers, mitigates error-cascades, and improves final discussion accuracy by an absolute 10.5%. Thus, this is a lightweight and efficient way to reduce model sycophancy during discussions and subsequently improve downstream accuracy.
Anthology ID:
2026.sigdial-1.56
Volume:
Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue
Month:
August
Year:
2026
Address:
Atlanta, Georgia, USA
Editors:
Jinho D. Choi, Yun-Nung Chen, Kotaro Funakoshi, Ali Emami
Venue:
SIGDIAL
SIG:
SIGDIAL
Publisher:
Association for Computational Linguistics
Note:
Pages:
795–814
Language:
URL:
https://aclanthology.org/2026.sigdial-1.56/
DOI:
Bibkey:
Cite (ACL):
Vira Kasprova, Amruta Parulekar, Abdulrahman AlRabah, Krishna Agaram, Ritwik Garg, Sagar Jha, Nimet Beyza Bozdag, and Dilek Hakkani-Tur. 2026. Too Polite to Disagree: Understanding Sycophancy Propagation in Multi-Agent Systems. In Proceedings of the 27th Annual Meeting of the Special Interest Group on Discourse and Dialogue, pages 795–814, Atlanta, Georgia, USA. Association for Computational Linguistics.
Cite (Informal):
Too Polite to Disagree: Understanding Sycophancy Propagation in Multi-Agent Systems (Kasprova et al., SIGDIAL 2026)
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PDF:
https://aclanthology.org/2026.sigdial-1.56.pdf