Beyond Profile: From Surface-Level Facts to Deep Persona Simulation in LLMs

Zixiao Wang, Duzhen Zhang, Ishita Agarwal, Shen Gao, Le Song, Xiuying Chen


Abstract
Previous approaches to persona simulation large language models (LLMs) have typically relied on learning basic biographical information, or using limited role-play dialogue datasets to capture a character’s responses. However, a holistic representation of an individual goes beyond surface-level facts or conversations to deeper thoughts and thinking. In this work, we introduce CharacterBot, a model designed to replicate both the linguistic patterns and distinctive thought patterns as manifested in the textual works of a character. Using Lu Xun, a renowned Chinese writer as a case study, we propose four training tasks derived from his 17 essay collections. These include a pre-training task focused on mastering external linguistic structures and knowledge, as well as three fine-tuning tasks: multiple-choice question answering, generative question answering, and style transfer, each aligning the LLM with Lu Xun’s internal ideation and writing style. To optimize learning across these tasks, we introduce a CharLoRA parameter updating mechanism, where a general linguistic style expert collaborates with other task-specific experts to better study both the language style and the understanding of deeper thoughts. We evaluate CharacterBot on three tasks for linguistic accuracy and opinion comprehension, demonstrating that it significantly outperforms the baselines on our adapted metrics. We hope this work inspires future research on deep character persona simulation LLMs: https://github.com/zxwang63/characterbot
Anthology ID:
2025.findings-acl.1094
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
21239–21257
Language:
URL:
https://preview.aclanthology.org/display_plenaries/2025.findings-acl.1094/
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Bibkey:
Cite (ACL):
Zixiao Wang, Duzhen Zhang, Ishita Agarwal, Shen Gao, Le Song, and Xiuying Chen. 2025. Beyond Profile: From Surface-Level Facts to Deep Persona Simulation in LLMs. In Findings of the Association for Computational Linguistics: ACL 2025, pages 21239–21257, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Beyond Profile: From Surface-Level Facts to Deep Persona Simulation in LLMs (Wang et al., Findings 2025)
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PDF:
https://preview.aclanthology.org/display_plenaries/2025.findings-acl.1094.pdf