There’s a fascinating book called Don’t Sleep, There Are Snakes by Daniel Everett that covers the Piraha people in the Amazon.

Their language is unusual: no recurrent sentences, almost no discussion of the past. I’m not suggesting they are unconscious but there appears to be something different going on with the Piraha sociolinguistically.

It is an interesting book, but as far as I know no one has verified Everett's work. I've just noticed this article that talks about it: https://news.mit.edu/2016/data-amazonian-piraha-language-deb...