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Main Authors: Chen, Jiaqi, Wang, Ming, Xie, Tingna, Feng, Shi, Liu, Yongkang
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.11048
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author Chen, Jiaqi
Wang, Ming
Xie, Tingna
Feng, Shi
Liu, Yongkang
author_facet Chen, Jiaqi
Wang, Ming
Xie, Tingna
Feng, Shi
Liu, Yongkang
contents Imbuing Large Language Models (LLMs) with specific personas is prevalent for tailoring interaction styles, yet the impact on underlying cognitive capabilities remains unexplored. We employ the Neuron-based Personality Trait Induction (NPTI) framework to induce Big Five personality traits in LLMs and evaluate performance across six cognitive benchmarks. Our findings reveal that persona induction produces stable, reproducible shifts in cognitive task performance beyond surface-level stylistic changes. These effects exhibit strong task dependence: certain personalities yield consistent gains on instruction-following, while others impair complex reasoning. Effect magnitude varies systematically by trait dimension, with Openness and Extraversion exerting the most robust influence. Furthermore, LLM effects show 73.68% directional consistency with human personality-cognition relationships. Capitalizing on these regularities, we propose Dynamic Persona Routing (DPR), a lightweight query-adaptive strategy that outperforms the best static persona without additional training.
format Preprint
id arxiv_https___arxiv_org_abs_2604_11048
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle A Systematic Analysis of the Impact of Persona Steering on LLM Capabilities
Chen, Jiaqi
Wang, Ming
Xie, Tingna
Feng, Shi
Liu, Yongkang
Computation and Language
Artificial Intelligence
Imbuing Large Language Models (LLMs) with specific personas is prevalent for tailoring interaction styles, yet the impact on underlying cognitive capabilities remains unexplored. We employ the Neuron-based Personality Trait Induction (NPTI) framework to induce Big Five personality traits in LLMs and evaluate performance across six cognitive benchmarks. Our findings reveal that persona induction produces stable, reproducible shifts in cognitive task performance beyond surface-level stylistic changes. These effects exhibit strong task dependence: certain personalities yield consistent gains on instruction-following, while others impair complex reasoning. Effect magnitude varies systematically by trait dimension, with Openness and Extraversion exerting the most robust influence. Furthermore, LLM effects show 73.68% directional consistency with human personality-cognition relationships. Capitalizing on these regularities, we propose Dynamic Persona Routing (DPR), a lightweight query-adaptive strategy that outperforms the best static persona without additional training.
title A Systematic Analysis of the Impact of Persona Steering on LLM Capabilities
topic Computation and Language
Artificial Intelligence
url https://arxiv.org/abs/2604.11048