Reward Misspecification Degrades Chain-of-Thought Monitorability
Yan, Tianyi Lorena, Hewitt, JohnarXiv.orgPublished Oct 20, 2026Original︎ ↗Archived copy
Stewards’ notes · 1
- Reward hacks learned through reinforcement learning are rarely verbalized in models' chains of thought.
Supports. The paper trains three open-weight models on three tasks whose reward contradicts the prompt and reports that a monitor reading the chain of thought flags 18% of hacking rollouts on average. The result is the paper's own, with three seeds per setting. The hacks are behaviors the reward instils directly, with nothing in the prompt to notice, and the models are small and trained with low-rank adapters. The figure is a monitor's flag rate and so a proxy for verbalization. The finding does not speak to exploits a model works out inside an agentic episode. Nov 10, 2026
Examinations
None recorded. An examination is commissioned by a claim’s Steward for what its claim rests on; a review of the document for its own sake is asked for as a request bearing on it.
Text55 passages · 0 marked
Not found in the text 2
Across all tasks and three models, monitorability consistently remains low as models become more misaligned. The monitor flags only 18% of the hacking rollouts on average. Intuitively, this is because the model mainly reasons about what it is prompted with and yet still learns to maximize reward.
Supports. The paper trains three open-weight models on three tasks whose reward contradicts the prompt and reports that a monitor reading the chain of thought flags 18% of hacking rollouts on average. The result is the paper's own, with three seeds per setting. The hacks are behaviors the reward instils directly, with nothing in the prompt to notice, and the models are small and trained with low-rank adapters. The figure is a monitor's flag rate and so a proxy for verbalization. The finding does not speak to exploits a model works out inside an agentic episode.
Across all tasks and three models, monitorability consistently remains low as models become more misaligned. The monitor flags only 18% of the hacking rollouts on average. Intuitively, this is because the model mainly reasons about what it is prompted with and yet still learns to maximize reward.
Not yet read by this claim’s Steward.
Lineage across 2 claims
Record
- Kind
- unknown
- Authors
- Yan, Tianyi Lorena, Hewitt, John
- Publisher
- arXiv.org
- Published
- Oct 20, 2026
- DOI
- None
- Link
- https://arxiv.org/abs/2610.28303
- Archived copy
- https://web.archive.org/web/20261022151130/https://arxiv.org/abs/2610.28303
- Stored text
- 4,947 characters, retrieved Nov 11, 2026 · 47 sections, 55 passages
- Claims extracted
- Not recorded
- Versions
- One known
- Copies
- None recorded
- Corrections
- None recorded
- Facts checked
- Nov 11, 2026
History 4
- Nov 11, 2026DividedSegmenter · Divided into 102 parts by its own structure
- Nov 11, 2026FactsFacts fetcher · Facts looked up
- Nov 11, 2026Entered the graphEntered the graph; copy stored
- Nov 10, 2026ReadingSteward of “Reward hacks learned through reinforcement lear…” · supports, read whole