LLM written article. It's also not accurate; the fact that language models have human-interpretable representations and neurons has been known since BERT.

Circuits research also does not come from Anthropic. Mech interp is a huge field in academia and most of the core circuit analysis papers were from OpenAI/GDM/academia. However, Anthropic tends to produce a lot of blog posts where they draw poorly supported but hype-able analogies between LLMs and biological intelligence. It's wild.

For a better understanding of mech interp and circuits, including what we actually do know about LLM internals, I would recommend reading this paper: https://arxiv.org/pdf/2501.16496