I’ve been watching videos of pets (dogs, cats) being “button trained”—being taught to use (primitive, non-syntactic) language by making associations between things/acts/emotional states and the pressing of one or another audio-playing buttons that has been placed on the floor.
It has very much driven home the point for me, that “spoken language” is actually not something inherent and instinctual to humans (or to any species); but rather is a technology. It’s just a technology that’s rather simple to learn, if you have the right underlying hardware acceleration (e.g. a cerebral cortex)—and, crucially, a teacher. For other intelligent mammals, apparently the teacher is the only component they’re missing!
Language is a technology that humans in particular find very intuitive—at least at a young age when our brains are malleable—but not one we inherently start with. We absorb it easily if we’re immersed in a society where everybody uses language from birth. But in situations where that’s not true (feral children, some very broken homes) we don’t.
In a world where every human being instantly had all entrained structure in their neocortex erased, such that we were “reduced” to being upright hairless apes with the capacity for language but no knowledge of it, I don’t think we’d just instantaneously come up with the idea of language and begin attempting to develop languages to communicate, the way modern people instantly try to develop a creole of the languages they do know, when stuck in a situation with people who share no common language with them.
The idea to associate concepts with specific mouth-noises—and to condition others to use those same mouth-noises for the same concepts, to facilitate transmission of thought—might randomly arise in a few people, but it’d need to catch on and spread from there, just like any other technology. It would either need to be observed and copied, or actively taught.
And I hypothesize that that is what happened (pre)historically: at some point, there were several memetic “waves” spreading increasingly-technologically-advanced (e.g. syntactic, expressive) forms of language across human populations with brains already structurally amenable to them. Of course, each wave would only be a struggle to the generation that pioneered it; the next generation, being immersed in that new, more-complex language form from birth, would find it similarly intuitive.
(This makes me wonder whether we’ve yet hit the “limits of linguistic expressiveness” for our current brain size, such that we’d need to unlimit e.g. average skull diameter at birth to let us get any fancier with language; or whether we’ve still got some, ah, “headroom” left.)