I’m pretty sure that there are a number of human populations whose languages never had a written form - for example, several African groups and many native American tribes.
I am wondering if any human groups have ever been found who did not develop even a spoke language. The capability for language is apparently built into the human brain, but are/were there any groups who somehow never used it?
I’m pretty sure that no population in modern times has been found that didn’t have a spoken language. It would be such a gigantic deal that there’s no way it could not be talked about everywhere.
It depends on what you’re willing to call a “population”, and whether you count sign languages as “spoken”.
Well, everywhere except the population without…yeah, I went there.
Seriously, speech is a pretty fundamental capability in human interactions, and aside from people who suffer congenital deafness, the formation of some kind of language is a part of childhood development. Children will begin to babble seeming nonsense long before they master a shared vocabulary and grammar, but as parents know even those sounds have semantic content. In essence, children create their own language even before they adapt tomthat of the culture they live in. Languages vary in complexity and grammatical structure (although there are some universal elements to both) but all humna cultures in history have had a spoken language.
Stranger
As I understand it, noted political dissident Noam Chomsky gained his initial notoriety as a linguist who postulated that language is hard wired into humans.
https://www.livestrong.com/article/224250-chomskys-theory-on-language-development-in-children/
That language is hard wired into humans goes way back to early philosophers. Chomsky’s deal was that particular types of syntactic elements are hard wired. All “proven” by vigorous arguing over many years.
I studied Pinker’s The Language Instinct in a high school class and at least in that point in my life it was fairly persuasive to me that some sort of natural ability to acquire language must be present in growing children in order to explain everything that we can see about language acquisition and times when there is no language acquisition. Children of parents speaking pidgin languages manage to develop it into a fully workable creole language. Children taken from one culture and thrust into another having learned the rudiments of the first culture’s language are able to pick up the second culture’s language with little trouble while being able to keep their proficiency in their first language. Adults that have somehow been brought up without any language at all find it very difficult to learn one, while children obviously pick it up from scratch all the time. Plus there are arguments on the structure of language that Chompsky was the first to really start on that suggest that some sort of foundation for language is imprinted in the human genome, with the particular details of the language being filled in when the child learns one.
As to deaf societies, check out Martha's Vineyard Sign Language - Wikipedia - congenital hereditary deafness in the population on Martha’s Vineyard made them develop their own sign language used by hearing and deaf alike. If people somehow were prevented from vocalizing, they would almost certainly work out a sign language. There also was a lingua franca sign language in the Plains Indians of North America: Plains Indian Sign Language - Wikipedia
I’m sure that an anthropologist will be along shortly to give chapter and verse but I believe it has been determined from the steps required to manufacture and use tools that language was required and this preceded the hominid diaspora from Africa.
Australian indigenous people had elaborate sign languages, which was additional to their usual 3-6 spoken languages. There are plenty of times where silence is required - during hunting, in many religious observances, where there are specific proscriptions to talking to someone such as during mourning.
This is the origin of monolingual malarky from early explorers that Aboriginal people knew masonic signs and therefore were connected to the ancient Phoenicians blah blah blah…
No, there are no “populations” that don’t have spoken language, using that term the way anthropologists do. But it’s a mistake to think that any human populations we can identify even in historical times actually developed spoken language. Anthropologists put the existence of fully articulate human language at no later than about 60,000 years ago, and probably a lot earlier than that.
Sign languages have, of course, been developed even in recent times, but I don’t think that is what the OP is asking about.
And monasteries which are under a vow of silence rather quickly develop elaborate sign languages for the monks to use.
Yes - it isn’t a normal pattern for a bunch of non-speaking humans to be thrown together and then create a language.
Instead, very close to 100% of all humans that have ever lived (for at least the past 600 centuries or so) learned language as a child. Groups have frequently become isolated, which led to their language evolving, eventually into something not comprehensible to ancestors far enough back in time. But the language that a population “develops” is always based on what came before.
By this argument, a population of humans without language is essentially impossible.
Isn’t that straight-up cheating? After all, the point of the vow is not to talk at all, not merely in a spoken language. It’s true, though, that monks often work together on certain tasks so some basic information needs to be communicated (but a full sign language?)
I heard that some of these monasteries have a rotating designated speaker, for example to read the newspaper headlines out loud to everybody.
Yes, it was straight up cheating. It’s not clear to me why the monastic system gradually fell apart, but it did, and people noticed and commented on it at the time.
In general, any time you have a group of people who can’t verbalize for whatever reason, they’ll come up with signs to communicate. The complexity and completeness of the signs developed will depend on the context: a school for the deaf where students are not being taught an already-existing Sign Language will see one be born.
Spanish Sign Language is an evolution of the Sign Language used by Cister monks who have a vow of silence - of silence, not of non-communication. The first School for the Deaf in Spain was a Cister monastery, one of whose monks had the idea of accepting deaf novices, making it clear that like any other novice they didn’t have to take vows or to stay in the monastery forever, and these people would learn at least a bit of each of the monastery’s trades (just like any other novice) and then choose one or more to learn further (j.l.a.o.n.), and those who left would then have a trade to work on and the hearing ex-novices could interpret for the deaf ones and… aaaand the abbot thought it was a great idea. Or maybe he was just tired of having the monk on his face all day, but in any case they did it 
The vow is of very specifically of silence. The idea is not to avoid communication; monks aren’t supposed to be solipsists. The idea is to avoid disturbing the other monks in their meditations and their work. You can talk so long as you’re not being noisy. Cister Sign is not a cheat, it’s a way to solve the problem of “I need to give instructions to my novice student without making noise”.
Those are good points. However, it should be noted that in no case is the vow of silence a trick or gimmick (and thus perhaps something to be worked around); it is an essential part of avoiding distractions to the monastic life. So instructing novices is OK, but talking about the latest football results is not OK just because one does it without speaking!
Some orders make it pretty explicit in their statutes; for example, the Carthusian Order (stat crux dum volvitur orbis !) mention:
and even for the lay monks we have
Therefore, beyond not disturbing others by making noise, the intention is one of avoiding communication, not all communication but non-essential mundane communication (cf. books of learning are good but political news/gossip are particular anathema). Instructing a novice via spoken language would be OK in this order; why wouldn’t it be?
I thought the whole “vow of silence” thing was exaggerated. What orders required a vow? Most of what I can find just suggests certain time periods of the day where strict silence must be maintained, and in a lot of traditions, the “silence” isn’t even literal no talking, but no talking without a sense of purpose, or something to that effect.
And I personally just thought the goal was silence and discipline in maintaining silence and keeping a sense of prayer/reflection, not an outright ban on communication. That doesn’t make any sense to me, but I suppose a lot of religious stuff doesn’t make sense to me.
