Detecting Strategic Deception Using Linear Probes — LessWrong
Can you tell when an LLM is lying from the activations? Are simple methods good enough? We recently published a paper investigating if linear probes detect when Llama is deceptive. Abstract: AI models might use deceptive strategies as part of scheming or misaligned behaviour. Monitoring outputs alone is insufficient, since the AI might produce seemingly benign outputs while its internal reasoning is misaligned. We thus evaluate if linear probes can robustly detect deception by monitoring model activations. We test two probe-training datasets, one with contrasting instructions to be honest or deceptive (following Zou et al., 2023) and one of responses to simple roleplaying scenarios. We test whether these probes generalize to realistic settings where Llama-3.3-70B-Instruct behaves deceptively, such as concealing insider trading (Scheurer et al., 2023) and purposely underperforming on safety evaluations (Benton et al., 2024). We find that our probe distinguishes honest and deceptive resp
x Detecting Strategic Deception Using Linear Probes — LessWrong Language Models (LLMs) Apollo Research (org) Interpretability (ML & AI) AI Frontpage 2025 Top Fifty: 14 % 104 Detecting Strategic Deception Using Linear Probes by Nicholas Goldowsky-Dill , bilalchughtai , StefanHex , Marius Hobbhahn 6th Feb 2025 AI Alignment Forum 2 min read 9 104 Ω 46 This is a linkpost for https://arxiv.org/abs/2502.03407 Can you tell when an LLM is lying from the activations? Are simple methods good enough? We recently published a paper investigating if linear probes detect when Llama is deceptive. Abstract: AI
related reading
- Chapter 1: Transformer Interpretability - ARENAlearn.arena.education
- [2401.05566] Sleeper Agents: Training Deceptive LLMs that Persist Through Safety Trainingarxiv.org
- [2602.15515] The Obfuscation Atlas: Mapping Where Honesty Emerges in RLVR with Deception Probesarxiv.org
- Deep Deceptiveness — LessWronglesswrong.com
- How confessions can keep language models honest | OpenAIopenai.com
- How well do truth probes generalise? — LessWronglesswrong.com
- Simple probes can catch sleeper agents \ Anthropicanthropic.com
- [2512.11949] Neural Chameleons: Language Models Can Learn to Hide Their Thoughts from Unseen Activation Monitorsarxiv.org
- Structure and Interpretation of Deep Networkssidn.baulab.info
- Introspection Adapters: Training LLMs to Report Their Learned Behaviorsarxiv.org
- Strategic Dishonesty Can Undermine AI Safety Evaluations of Frontier LLMsarxiv.org
- [2604.16812] Introspection Adapters: Training LLMs to Report Their Learned Behaviorsarxiv.org