Toward Robust Personalized Alignment for LLMs: Mitigating Persona Drift in Multi-Turn Dialogue

Youyuan Zhang, Siyuan Li, Fangming Liu, Jing Li


Abstract
Persona drift remains a central challenge for personalized language models, as user profiles evolve over long interactions rather than remain permanently fixed. Models must therefore revise persistent persona states when preferences genuinely change, while avoiding updates driven by transient, ambiguous, or unresolved observations. We propose CORE, which separates turn-local evidence from persistent persona-state revision and selectively updates grounded user preferences through uncertainty-aware belief revision. We also introduce PERSIST, a held-out post-anchor benchmark for persona-state robustness under sequential interaction stress, covering ambiguity, conflict, and controlled social influence. Across ALOE, PersonaChat, and PERSIST, CORE improves personalized alignment and robustness, with complementary gains in normalized closed-slot state fidelity. Human evaluation and mechanistic controls further support explicit update control beyond stronger generation or persistent memory alone.
Anthology ID:
2026.findings-emnlp.666
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
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
13978–14006
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.666/
DOI:
Bibkey:
Cite (ACL):
Youyuan Zhang, Siyuan Li, Fangming Liu, and Jing Li. 2026. Toward Robust Personalized Alignment for LLMs: Mitigating Persona Drift in Multi-Turn Dialogue. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 13978–14006, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Toward Robust Personalized Alignment for LLMs: Mitigating Persona Drift in Multi-Turn Dialogue (Zhang et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.666.pdf