This is a bit of a scatter gun approach. My intent here isn’t to ‘debate’ or ‘argue’. My intent is to explore the subject matter beyond the initial post made by you - I’m not really interested in talking about Merge in depth because I can, and have, read up on that elsewhere.
Well fine, but that's not saying much. Of course you agree language is something separate from, say, digestion. The visual system is separate from the circulatory system as an object of study. Are there overlaps and interactions? Yes, of course. I don't disagree with that. But we're trying to find out what language is and what the principles underlying it are. — Xtrix
This is just speculation as much as what I have mentioned regarding language acquisition in adulthood. Why dismiss instances of people who have difficulty in using language or who have been cut of from language (and human contact to some degree or other simply because the cases are in the low numbers). Anyway, there is no need to go back and forth over this ...
Something that is apparent from neurogenesis is the plasticity of the human brain. The acquisition of ‘communicative language’ (spoken/signed) shifts the activity fro the right hemisphere more into the left hemisphere - although some argue this is just a matter of motor function. Is the motor function necessary for language? It seems so on the surface but that may be too hasty to hold to.
Note: not interested in getting into semantics over the meaning of ‘function’ or ‘language’. It was apparent enough to me, before looking in to Chomsky, that ‘language’ is a loaded term and that linguistics - as a science - has many softer and harder edges in terms of psychology and computational analysis.
If we’re talking about evolution then I’m afraid you cannot ignore ‘anthropology’ and then make it out to be some can of non-science - it is a science, and like ‘linguistics’ it has softer and harder edges to it. The genetic factor has been pursued in term of ‘language genes’ but that whole endeavor has pretty much been dropped because the system is far too complex and there is very little evidence that singular genes act in isolation.
Let us take the example of ‘the man with no language’ and ask how we can identify some ‘innate’ capacity fro language. If, like you say, he always had the capacity for language there untapped then how come feral children cannot develop a language as fully as him? It seems obvious the telling factor is he lived in human society. This leads me to think that it is more a matter of associating abstract ideas with commonly lived features of the environment - as example if you show chimp faces to infants they develop the ability to distinguish monkey faces from each other, and it isn’t a huge leap to see that humans brought up without exposure to human features won’t find it easy to distinguish between different human faces (people to them will look fairly generic). This is a well known developmental feature of human’s (IOR - inhibition of return).
Let’s move onto other areas like the youngest language we know of developed by deaf children in Nicaragua. As I‘vepreviously mentioned the early stage of this language - its initial form - showed that fully grown adults were unable to hold both object colour and position in mind at once when asked where such and such an object was located (eg. near the blue box in the left corner). This is something a rat cannot do nor a 5 year old child - yet the adults were quite capable of solving other complex problems. The younger speakers had picked up more complex terms in language communication that dealt with this and many adults then learnt to apply this to their view of the world.
What is going on there? If the ability to perceive the objective world is shaped by word concepts in this way then does this mean it takes a huge cognitive leap to open up a more comprehensive amalgam of sensory data?
Let’s move onto other studies regarding ‘attention’. I’m sure you’ve heard of ‘blind-sightedness’ where subjects are consciously ‘blind’ yet they can navigate around obstacles. If we look at instances of stoke victims too who go through a recovery period they describe their lack of ability to ‘see’ one half of their body/face as more or less a lack of ‘attention’. In this respect we could suggest that language is more or less something like a mechanism of ‘attention’ - a mode of thought expression (not necessarily ‘external’ - meaning directed toward another individual). This would be where many Witty a fanboy would scream ‘there is no Private Language’ yet they are probably not quite aware of what Witty was saying and how he defined Language - he defined it in such a manner as to make any ‘Private Language’ impossible by way of how he framed the definition of “Language” ... nothing wrong with that, but I’m not going to misapply semantic value from one instance to another to suit my or anyone else’s purpose.
Then there are studies about split brain patients where we can see perfectly well that the separate hemispheres communicate with each other externally - one side of the brain guiding the other. In fact, when asked the same question each hemisphere gives a different answer and has different ‘attitudes’. It could be the ‘language’ faculty in question is nothing more than an externalised ‘communicative’ function between lobes/hemispheres.
Anyway, food for thought there (there are too many items to go into in detail in one post so thought I’d throw some out together). None of this is necessarily about Chomsky’s ideas or anyone else’s particular ideas of language. I just don’t look at this subject matter as self-contained or any position as writ in stone.
Now, back to the original quote from you above:
Are there overlaps and interactions? Yes, of course. I don't disagree with that. But we're trying to find out what language is and what the principles underlying it are.
Maybe it isn’t really a ‘distinct’ item at all - other than in a communicative sense. I don’t look at a knife and fork and think ‘knife and fork’, the ‘and’ is not perceived in any manner at all. What I mentioned above about signed language and the ability to apply ‘and’ was down to ‘communicative language’ not some internalised thought - that is not to say I don’t view ‘language’ (in the broader sense of the term) as function of thought. If the underlying principles is ‘thought’ then why are we not asking what ‘thought’ is? I don’t need ‘words’ to think or solve complex problems, yet it is apparently the case that articulating thought (an explicit example being the ‘written word’) allows me to ‘view’ my thoughts consciously - which hints at ‘theory of mind’.
Piaget did some interesting studies on children and how the used monologues in their early years; many times without concern for other listeners. I guess you’re familiar with that too?
The developmental stages in childhood often show a speeded up version of human evolution, we crawl on all fours rather than stand and walk - if raised by wolves we’d continue to crawl on all fours and our anatomy would take the strain.
Mouth are for eating and lungs are for breathing. The underlying principles of language must then be ‘eating’ and ‘breathing’ - the brain on top of this mechanism combines this with locomotion (to find air to breath and food to eat) and a memory to map the world for more efficient sourcing of said ‘food’ and ‘air’. So why not just say language’s underlying principles originate in memory and environmental mapping, which then became a function of consciousness and through ‘theory of mind’ took on a communicative function for thought too that was established by way of vocalisation, motor ability and spacial awareness through an ability to direct attention via memories/mapping/models.
If you do a quick TEDtalk search for ‘my child’s first words’ you’ll see how ‘vocal signs’ are mapped out in a landscape - nothing to do with grammar but it’s interesting to see how thoughts and experiences are accumulated in space and remembered.
One of my general ideas is that ‘language’ is more of less about an emotional narrative function used to instill memories and develop a set of thoughts that led to free formed abstract concepts - the rest is a matter of externalising and exploring differences of thought in ever growing intricacy. Any kind of ‘recursion’ is a matter of memory so maybe ‘language’ is spandrel of ‘memory’. After all explicit memory (‘semantic’ and ‘episodic’) are far more important for thought than anything else (without them there is no ‘thought’). The ‘language’ thing looks to me to be something to do with ‘episodic’ memory, yet I don’t believe ‘language’ preceded ‘thought’, it only preceded ‘communicative language’.