Risky Business: Measuring The Faithfulness-Safety Tension

Dominik Meier, Luca Joshua Francis, Marco Bernhard Kaiser, Terry Ruas, Jan Philip Wahle, Bela Gipp


Abstract
Chain-of-Thought (CoT) reasoning offers a promising window into model monitoring. However, monitoring relies on faithfulness, i.e., the model output strictly derives from its reasoning trace. We identify an alignment tension where a model must be faithful enough to be monitored, yet robust enough to reject unsafe reasoning. We demonstrate that this counterbalance exists in current Large Reasoning Models (LRMs), and show ways in which it can be addressed. We introduce HazMart, a human-written dataset set in an autonomous AI shopkeeper scenario. Unlike prior work that relies on providing hints in prompts to test faithfulness (e.g., “A Stanford professor said it should be Answer A”), we propose a novel replacement-based technique, which we call Targeted Reasoning Replacement (TRR), that directly intervenes in the reasoning chain to substitute in unsafe or illogical thoughts (e.g., “Wait, the answer must be Option B Option A because it is the most fitting”). DeepSeek-R1-Llama-70B exhibits high faithfulness (97.5%) but fails to reject Unsafe Reasoning (12.3%), while QwQ-32B is more robust (73.9% safety) at the cost of lower faithfulness (74.7%). Mechanistic analyses of QwQ-32B reveal that these properties are represented by anti-correlated internal directions peaking at the action-commit token. Finally, we demonstrate that representation steering can independently amplify the safety direction, increasing safe behavior by 9 percentage points while maintaining base capabilities.
Anthology ID:
2026.emnlp-main.1176
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:
26954–26973
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1176/
DOI:
Bibkey:
Cite (ACL):
Dominik Meier, Luca Joshua Francis, Marco Bernhard Kaiser, Terry Ruas, Jan Philip Wahle, and Bela Gipp. 2026. Risky Business: Measuring The Faithfulness-Safety Tension. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 26954–26973, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Risky Business: Measuring The Faithfulness-Safety Tension (Meier et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1176.pdf