AutoLexSteer: Automatic Contrast Construction for Lexical Activation Steering

Shuhe Wang, Lachlan Cowley, Eduard Hovy, Jey Han Lau


Abstract
Steering vectors have rapidly emerged as a popular and effective method for guiding the output of LLMs in very specific ways. But constructing accurate steering vectors is a difficult manual process due to the opacity of embeddings. We introduce Hangman, a novel type of steering vector that operates using word senses, as well as AutoLexSteer, the first fully automated process for building steering vectors. AutoLexSteer employs families of closely-related words extracted from WordNet to specify both the steering source to be avoided and the desired steering target. The steering vectors are quite precise, can be used to steer at the level of words and sets of word senses (meanings), and are able to steer certain LLM behaviors like sycophancy. The dataset and code can be found at https://github.com/ShuheWang1998/autolexsteer.
Anthology ID:
2026.findings-emnlp.2202
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:
47149–47174
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2202/
DOI:
Bibkey:
Cite (ACL):
Shuhe Wang, Lachlan Cowley, Eduard Hovy, and Jey Han Lau. 2026. AutoLexSteer: Automatic Contrast Construction for Lexical Activation Steering. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 47149–47174, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
AutoLexSteer: Automatic Contrast Construction for Lexical Activation Steering (Wang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2202.pdf