Evolutionary brain development.
We all come from monke, monkey from 10 million years ago would definitely be unable to even learn spoken language at a basic level. Would he even have the anatomy to produce the required sounds? I don't think so.
What about monke from 1 million years ago? 200 thousand years ago?
ChatGpt says spoken language only emerged 50k - 200k years ago and that a cavemen baby from 200k years ago could learn spoken language if brought up by modern parents.
But I prefer human answers over AI slop.