The Effectiveness of Style Vectors for Steering Large Language Models: A Human Evaluation

Fuente: arXiv
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Main Authors: Diallo, Diaoulé, Dworatzyk, Katharina, Jentzsch, Sophie, Schütt, Peer, Theis, Sabine, Hecking, Tobias
Format: Preprint
Published: 2026
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author Diallo, Diaoulé
Dworatzyk, Katharina
Jentzsch, Sophie
Schütt, Peer
Theis, Sabine
Hecking, Tobias
author_facet Diallo, Diaoulé
Dworatzyk, Katharina
Jentzsch, Sophie
Schütt, Peer
Theis, Sabine
Hecking, Tobias
contents Controlling the behavior of large language models (LLMs) at inference time is essential for aligning outputs with human abilities and safety requirements. \emph{Activation steering} provides a lightweight alternative to prompt engineering and fine-tuning by directly modifying internal activations to guide generation. This research advances the literature in three significant directions. First, while previous work demonstrated the technical feasibility of steering emotional tone using automated classifiers, this paper presents the first human evaluation of activation steering concerning the emotional tone of LLM outputs, collecting over 7,000 crowd-sourced ratings from 190 participants via Prolific ($n=190$). These ratings assess both perceived emotional intensity and overall text quality. Second, we find strong alignment between human and model-based quality ratings (mean $r=0.776$, range $0.157$--$0.985$), indicating automatic scoring can proxy perceived quality. Moderate steering strengths ($λ\approx 0.15$) reliably amplify target emotions while preserving comprehensibility, with the strongest effects for disgust ($η_p^2 = 0.616$) and fear ($η_p^2 = 0.540$), and minimal effects for surprise ($η_p^2 = 0.042$). Finally, upgrading from Alpaca to LlaMA-3 yielded more consistent steering with significant effects across emotions and strengths (all $p < 0.001$). Inter-rater reliability was high (ICC $= 0.71$--$0.87$), underscoring the robustness of the findings. These findings support activation-based control as a scalable method for steering LLM behavior across affective dimensions.
format Preprint
id arxiv_https___arxiv_org_abs_2601_21505
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The Effectiveness of Style Vectors for Steering Large Language Models: A Human Evaluation
Diallo, Diaoulé
Dworatzyk, Katharina
Jentzsch, Sophie
Schütt, Peer
Theis, Sabine
Hecking, Tobias
Artificial Intelligence
Computation and Language
Human-Computer Interaction
Controlling the behavior of large language models (LLMs) at inference time is essential for aligning outputs with human abilities and safety requirements. \emph{Activation steering} provides a lightweight alternative to prompt engineering and fine-tuning by directly modifying internal activations to guide generation. This research advances the literature in three significant directions. First, while previous work demonstrated the technical feasibility of steering emotional tone using automated classifiers, this paper presents the first human evaluation of activation steering concerning the emotional tone of LLM outputs, collecting over 7,000 crowd-sourced ratings from 190 participants via Prolific ($n=190$). These ratings assess both perceived emotional intensity and overall text quality. Second, we find strong alignment between human and model-based quality ratings (mean $r=0.776$, range $0.157$--$0.985$), indicating automatic scoring can proxy perceived quality. Moderate steering strengths ($λ\approx 0.15$) reliably amplify target emotions while preserving comprehensibility, with the strongest effects for disgust ($η_p^2 = 0.616$) and fear ($η_p^2 = 0.540$), and minimal effects for surprise ($η_p^2 = 0.042$). Finally, upgrading from Alpaca to LlaMA-3 yielded more consistent steering with significant effects across emotions and strengths (all $p < 0.001$). Inter-rater reliability was high (ICC $= 0.71$--$0.87$), underscoring the robustness of the findings. These findings support activation-based control as a scalable method for steering LLM behavior across affective dimensions.
title The Effectiveness of Style Vectors for Steering Large Language Models: A Human Evaluation
topic Artificial Intelligence
Computation and Language
Human-Computer Interaction
url https://arxiv.org/abs/2601.21505