Regarding the conclusion about language-invariant reasoning (conceptual universality vs. multilingual processing) it helps understanding and becomes somewhat obvious if we regard each language as just a basis of some semantic/logical/thought space in the mind (analogous to the situation in linear algebra and duality of tensors and bases).
The thoughts/ideas/concepts/scenarios are invariant states/vector/points in the (very high dimensional) space of meanings in the mind and each language is just a basis to reference/define/express/manipulate those ideas/vectors. A coordinatization of that semantic space.
Personally, I'm a multilingual person with native-level command of several languages. Many times it happens, I remember having a specific thought, but don't remember in what language it was. So I can personally sympathize with this finding of the Anthropic researchers.
The thoughts/ideas/concepts/scenarios are invariant states/vector/points in the (very high dimensional) space of meanings in the mind and each language is just a basis to reference/define/express/manipulate those ideas/vectors. A coordinatization of that semantic space.
Personally, I'm a multilingual person with native-level command of several languages. Many times it happens, I remember having a specific thought, but don't remember in what language it was. So I can personally sympathize with this finding of the Anthropic researchers.