[tsimionescu]

The encoding I was talking about may well be something more abstract than 'imitate humans'. Still, babies don't generally try to imitate the sound of rattles or household sounds nearly as much as speech, so I still conclude that it is a safe assumption that there is something about sounds made by humans that is inherently interesting to them for some reason (instead of being a learned behavior).

Related to the second, the rate at which we learn, and the very specific order we learn things in, points very strongly in the direction that there is some built-in model that we train inside of. For example, essentially all babies first learn intonation before learning words. Also, most words are learned with an extremely small set of examples - at some ages, often hearing a word a single time is enough for the child to learn it (known as the 'poverty of the stimulus' problem). This has been mainstream understanding ever since behaviorism fell out of favor due to similar arguments by Chomsky.

[Quarrelsome]

> try to imitate the sound of rattles or household sounds nearly as much as speech

Well surely that's a case of the range of the vocal chords? Parrots are another intelligent creature that has better range and they imitate all sorts of sounds.

> Related to the second, the rate at which we learn, and the very specific order we learn things in, points very strongly in the direction that there is some built-in model that we train inside of.

Or that an action like walking requires one to put one foot ahead of the other, all other strategies in attempting to walk end in failure, which is why we don't see them.

I'd like to point out that all humans perceive intonation and its perceivable outside of language, that's why its easy to pick up, you don't need language to realise that someone is cross, or happy or sad. However considering autistic children cannot then maybe there are some genetic markers at play there at least.

[YeGoblynQueenne]

>> Well surely that's a case of the range of the vocal chords? Parrots are another intelligent creature that has better range and they imitate all sorts of sounds.

Parrots (and birds like mainas etc) immitate human sounds and all sorts of sounds, but they don't discriminate between, e.g., the sound made by a train whistle and the sound made by a human carer. I mean that a parrot will not learn to speak a human language by immitating its sounds, any more than it'll learn to speak train by immitating a train whistle.

Human babies don't just immitate their parents' sounds, they figure out what those sounds do and how they come together to form language and express meaning. That is a small miracle that we don't understand at all well and Chomsky is 100% right to speak of scientific wonderment, in its context. It is really mind-blowing that kids can eventually learn to speak without, for the vast majority of children, anyone around them having any idea how to teach a kid to speak in any systematic way. Not to mention the trouble that adults have in learning another language even given formal training in it (which perhaps is further evidence that we really don't know how to teach language, because we don't understand how it works, so again, how can we teach small children to speak a language, but not adults?).

Chomsky's universal grammar is really the simplest answer: children don't learn how to speak a human language, they already know how, and they only have to learn the vocabulary and syntax of the language of their parents. This only presuposes that humans have human biology, and that our biology is responsible for our language ability. We can't learn to fly because we don't have wings and parrots can't learn to speak because they don't have human brains.

[Edit: that it's the simplest answer doesn't mean it's the right answer, only that it's got a damn good chance to be it.]

[tsimionescu]

The range of the vocal chords is a reason why children can't successfully imitate these sounds, it doesn't directly explain why they wouldn't try.

[Quarrelsome]

maybe they do try and we just shrug it off as gurgling. Kids do make funny noises when they're vocalising.