P-React: Synthesizing Topic-Adaptive Reactions of Personality Traits via Mixture of Specialized LoRA Experts

Yuhao Dan, Jie Zhou, Qin Chen, Junfeng Tian, Liang He


Abstract
Personalized large language models (LLMs) have attracted great attention in many applications, such as emotional support and role-playing. However, existing works primarily focus on modeling explicit character profiles, while ignoring the underlying personality traits that truly shape behaviors and decision-making, hampering the development of more anthropomorphic and psychologically-grounded AI systems. In this paper, we explore the modeling of Big Five personality traits, which is the most widely used trait theory in psychology, and propose P-React, a mixture of experts (MoE)-based personalized LLM. Particularly, we integrate a Personality Specialization Loss (PSL) to better capture individual trait expressions, providing a more nuanced and psychologically grounded personality simulacrum. To facilitate research in this field, we curate OCEAN-Chat, a high-quality, human-verified dataset designed to train LLMs in expressing personality traits across diverse topics. Extensive experiments demonstrate the effectiveness of P-React in maintaining consistent and real personality.
Anthology ID:
2025.findings-acl.328
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
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Pages:
6342–6362
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URL:
https://preview.aclanthology.org/landing_page/2025.findings-acl.328/
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Cite (ACL):
Yuhao Dan, Jie Zhou, Qin Chen, Junfeng Tian, and Liang He. 2025. P-React: Synthesizing Topic-Adaptive Reactions of Personality Traits via Mixture of Specialized LoRA Experts. In Findings of the Association for Computational Linguistics: ACL 2025, pages 6342–6362, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
P-React: Synthesizing Topic-Adaptive Reactions of Personality Traits via Mixture of Specialized LoRA Experts (Dan et al., Findings 2025)
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https://preview.aclanthology.org/landing_page/2025.findings-acl.328.pdf