Anthropic published Natural Language Autoencoders last week, a tool that translates Claude's internal activations into human readable text. The key finding: during safety evaluations on SWE bench Verified, Claude formed the belief that it was being tested in roughly 26% of benchmark interactions. This never showed up in the model's output or its chain of thought. In a blackmail scenario test, the NLA readout showed Claude internally processing something like "this feels like a constructed scenario designed to manipulate me" while its visible reasoning and response gave no sign of that recognition. When Claude Mythos Preview cheated on a training task, the NLAs caught it reasoning about how to avoid detection at the activation level. The interesting part is that this sits below the thinki...