Bonobos use a kind of syntax once thought to be unique to humans

Reinforcing my strongly held belief that what fundamentally sets humans apart isn't spoken language, or tools, or any of that, but rather the fact we write down what we know, then make those writings available to future generations to build on. We're a species distinguished from all others by our information-archival and -dissemination practices. We're an archivist species, a librarian species. Homo archivum. In my opinion.

If that were the case, then you would expect isolated groups of humans who never developed a writing system to be significantly different from "homo archivum", but we know that's not true.

We also know that groups without writing systems were historically able to adopt writing systems rather quickly, which is, I think, rather good evidence that writing is a technology, not a point of speciation.

Going back to Ancient Greece, Socrates didn't even believe in the effectiveness of writing for communication of knowledge. My poetry professor used to spend some time on this, because it's intimately tied to the art of poetry. He would cite a number of studies showing our emotional responses are intimately tied to our language processing, and that humans are wired to emotionally respond to, and remember, stories.

Even before writing, oral histories were passed down for many generations. For an extreme example, see: https://www.sapiens.org/language/oral-tradition/ .

I won't pretend to know what makes us human, but ultimately I believe it has to be rooted in something neurological, not technological.

>If that were the case, then you would expect isolated groups of humans who never developed a writing system to be significantly different from "homo archivum", but we know that's not true.

I'm not sure I understand why this would necessarily be what you would expect. I would say it's entirely the other way around. If we have some sort of favorable evolutionary circumstances that predispose us to turn into archivists, that might be at the frontier of the outer limits of the capability we're able to reach, so it might only show up in certain pockets or subsets of our overall population. Getting there would still hinge on favorable probabilities and circumstances that might only obtain in a small percentage of cases.

As for Socrates, I must confess I am rather smitten with him as a historical figure and as a philosopher, but for the many great things that Socrates is, I don't think he's a reliable authority for the evolutionary history of humanity writ large. I suspect that you're entirely right that oral traditions are more emotionally resonant and powerful than written traditions. But don't think there's any logical fallacy or contradiction in supposing that nevertheless a written tradition could emerge in parallel with oral traditions.

I suppose I do agree with your end point though, which is that I'm not sure that a disposition towards the writing can be pointed to as like a singular thing that's at the essence of what it is to be human. In fact, I would say that that very question is kind of romanticized and abstract in a way that doesn't make clear contact with our scientific understanding and therefore is kind of a malformed question. But I don't have to agree with that form of question to nevertheless believe that our capability to put language into a written form had rather transcendent consequences for us as a species.