Mitigating Cultural Bias in LLMs via Multi-Agent Cultural Debate

Qian Tan, Lei Jiang, Yuting Zeng, Shuoyang Ding, Xiaohua Xu


Abstract
Large language models (LLMs) exhibit systematic Western-centric bias, yet whether prompting in non-Western languages (e.g., Chinese) can mitigate this remains understudied. Answering this question requires rigorous evaluation and effective mitigation, but existing approaches fall short on both fronts: evaluation methods force outputs into predefined cultural categories without a neutral option, while mitigation relies on expensive multi-cultural corpora or agent frameworks that use functional roles (e.g., Planner–Critique) lacking explicit cultural representation. To address these gaps, we introduce CEBiasBench, a Chinese–English bilingual benchmark, and Multi-Agent Vote (MAV), which enables explicit "no bias” judgments. Using this framework, we find that Chinese prompting merely shifts bias toward East Asian perspectives rather than eliminating it. To mitigate such persistent bias, we propose Multi-Agent Cultural Debate (MACD), a training-free framework that assigns agents distinct cultural personas and orchestrates deliberation via a "Seeking Common Ground while Reserving Differences” strategy. Experiments demonstrate that MACD achieves 57.6% average No Bias Rate evaluated by LLM-as-judge and 86.0% evaluated by MAV (vs. 47.6% and 69.0% baseline using GPT-4o as backbone) on CEBiasBench and generalizes to the Arabic CAMeL benchmark, confirming that explicit cultural representation in agent frameworks is essential for cross-cultural fairness.
Anthology ID:
2026.findings-acl.418
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
8600–8612
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.418/
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Bibkey:
Cite (ACL):
Qian Tan, Lei Jiang, Yuting Zeng, Shuoyang Ding, and Xiaohua Xu. 2026. Mitigating Cultural Bias in LLMs via Multi-Agent Cultural Debate. In Findings of the Association for Computational Linguistics: ACL 2026, pages 8600–8612, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Mitigating Cultural Bias in LLMs via Multi-Agent Cultural Debate (Tan et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.418.pdf
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