carbor1

It's common for linguistics consultants to request that recordings be held private for a certain span of time after their deaths--- that may be one factor.

Another thing that is a factor for certain communities is that some stories or songs are the cultural property of particular families. In that case, older members of the family may make recordings to be held for when the descendents are ready for them--- when they're old enough, or perhaps when the language has been revitalized so that people can understand them again.

I do fieldwork on a lamguage that lacks a written form, so I actually know quite a lot of illiterate people, and they are quite capable of complex and rational thought.

In a literate society like ours, we tend to equate language with writing, but they're not at all the same thing. I agree that language is necessary for complex thought, just not writing.

Wow, this article's claim that text is what enables us to think is incredibly elitist. Are illiterate people incapable of rational thought? Oral traditions are deep wellsprings of human knowledge and culture.

That being said, the authors are doing a lot of comparisons here! They ought to be reporting Dunn-Bonferroni corrected p-values.

No, not necessarily. It's standard practice to pick a p-value significance cut-off (0.05), but report the smallest such standard cut-off that any particular value meets. So "p < 0.001" is reported for values that meet that threshold. Anything over the cut-off is just not reported as significant.