Harvard and MIT paper traces reasoning control failures to "Okay" openers
The finding decouples chain-of-thought monitoring reliability from controllability benchmarks: a trivial token-level intervention accounts for much of the apparent control failure. Safety teams evaluating CoT faithfulness should report opening-word effects separately from information-hiding tasks. The paper spans 12 open models including Qwen3 and OLMo, so labs fine-tuning open-weight reasoners can reproduce the fix directly.
