Revising Context, Shifting Simulated Stance: Auditing LLM-Based Stance Simulation in Online Discussions

Xinnong Zhang, Wanting Shan, Hanjia Lyu, Zhongyu Wei, Jiebo Luo


Abstract
Large language models are increasingly used to simulate social media users and infer how individuals may respond to online discussions. However, it remains unclear whether these simulations reflect precise user-specific beliefs or whether they are highly sensitive to semantically independent changes in conversational contexts. In this work, we study counterfactual context revision as a framework for auditing LLM-based stance simulation. Given an original online conversation, we first infer a target user’s stance toward a specific topic. We then apply controlled revision strategies to the conversational context and simulate the user’s stance again under the revised context. We compare text-only revision strategies with a multimodal one that incorporates meme-based context and evaluate two main effectiveness metrics, i.e., average directional stance shift and stance transition rate. The results reveal effective and robust stance transitions in both text-only and multimodal strategies across different polarization-preference mechanisms. Our study contributes an evaluation framework for understanding the context sensitivity of LLM-based stance simulation (https://github.com/STARResearchLab/StanceShift). More broadly, it highlights both the promise and risk of using LLMs as proxies for social media users in social simulation.
Anthology ID:
2026.findings-emnlp.1600
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
34088–34107
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URL:
https://aclanthology.org/2026.findings-emnlp.1600/
DOI:
Bibkey:
Cite (ACL):
Xinnong Zhang, Wanting Shan, Hanjia Lyu, Zhongyu Wei, and Jiebo Luo. 2026. Revising Context, Shifting Simulated Stance: Auditing LLM-Based Stance Simulation in Online Discussions. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 34088–34107, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Revising Context, Shifting Simulated Stance: Auditing LLM-Based Stance Simulation in Online Discussions (Zhang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1600.pdf