REINS: Refusal-Enhanced Inhibitory Steering with Sparse Autoencoder Features

Kai-Xuan Ding, Hao-Xiang Xu, Ji-Hua Peng, Zi-Qi Chen, Jiaqi Wang, Zhen-Hua Ling


Abstract
Steering with Sparse Autoencoders (SAEs) offers a lightweight inference-time path for adapting the behavior of large language models without retraining. By exposing sparse and interpretable features, SAE steering provides a promising interface for safety control that guides harmful continuations toward refusal. However, we observe that complex wrappers can still undermine existing SAE steering methods on harmful prompts. To evaluate this failure mode systematically, we construct Generalized Undercover Instruction Safety Evaluation (GUISE), a dataset of harmful prompts with complex wrappers. Existing single direction SAE steering methods do not reliably produce refusals on harmful prompts, suggesting that refusal enhancement alone can be too weak when the harmful continuation path remains active. This motivates us to propose Refusal-Enhanced INhibitory Steering (REINS), which suppresses harmful continuation features and enhances safe refusal features in the same SAE feature space. Experiments on GUISE and other datasets show that prior methods either intervene too weakly or achieve only apparent safety through collapse, while REINS substantially reduces harmful responses, markedly improves safe refusals and largely preserves general capabilities.
Anthology ID:
2026.emnlp-main.1298
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
29541–29574
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1298/
DOI:
Bibkey:
Cite (ACL):
Kai-Xuan Ding, Hao-Xiang Xu, Ji-Hua Peng, Zi-Qi Chen, Jiaqi Wang, and Zhen-Hua Ling. 2026. REINS: Refusal-Enhanced Inhibitory Steering with Sparse Autoencoder Features. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 29541–29574, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
REINS: Refusal-Enhanced Inhibitory Steering with Sparse Autoencoder Features (Ding et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1298.pdf