I have to do another post on this.
http://asa.scitation.org/doi/abs/10.1121/1.1974668
This has been a pet theory of mine monkeys hearing is not very good below 8khz, down as much as 60db in the 4khz and below range where human speech primarily resides. Maybe they are basically hard of hearing in our spectral range? I wonder if anyone ever thought about making a special hearing aid for them to boost the low frequencies. Or maybe move the human speech up to their range (they can hears as high as 45Khz while humans cut off at 20khz). Maybe you could teach them to speak but it would be super high pitched and another device could shift it back down. Like a frequency up and down converter.
I had read that the spinal cord of monkeys and the small hole through which it must pass, does not permit the many nerves that are required to control the speech apparatus with sufficient accuracy for intelligible speech. I was surprised to find the article didn't mention this issue at all, either as an urban myth, or as a fact of anatomy. Has thinking moved on when it comes to this issue? Are Macaque monkeys somehow different in this regard?
I'd be interested in a citation for this, if you have one handy. I've read that he wrote about this in a letter but I haven't been able to find it. The closest I've been able to find is (via WP):
> The word [orangutan] comes from Bontius (1631, Hist. Nat. et Med. Ind. Orient.) who claimed that the Javanese had informed him that orang-utans could talk, ‘but do not wish to, lest they should be compelled to labour’.
Dellios, Paulette (2005). A Lexical Odyssey from the Malay World. The Proceedings of the European Integration-Between Tradition and Modernity Congress, Editura Universităţii "Petru Maior", Volume Number 1, 2005, ISSN 1844-2048, pp. 460-463. http://www.upm.ro/facultati_departamente/stiinte_litere/conf...
Bontius's book looks like the sort of thing Descartes would have read, so I'd be interested in reading his reaction.
>Mr. Clerselier has written me that you are expecting from him my Meditations... in order to present them to the queen of the land. ...If I had only been as wise as they say the savages persuaded themselves that the monkeys were, I never would have become known as a maker of books: Since it is said that they imagined that the monkeys could indeed speak, if they wanted to, but that they chose not to so lest they be forced to work. And since I had not the same prudence to abstain from writing, I now have neither as much liesure nor as much peace as I would have had if I had kept quiet. But since the mistake has already been made, and since I am now known by an infinity of people at the academy, who look askance at my writings and scour them for means of harming me, I do have great hope of being known to persons of great merit, whose power and virtue could protect me.
>Letter to Pierre Chanut (Nov. 1, 1646) as quoted by Amir Aczel, Descartes' Secret Notebook (2005) citing René Descartes: Correspondance avec Elizabeth et autres lettres (1989) ed., Jean-Marie and M. Beysaade, pp. 245-246.
I suspect the answer is similar to why a macaque can't play billiards even though it is physically capable of it.
It's not like macaque monkeys don't "speak" to each other, they do make sounds that indicate certain things that other monkeys understand. They just don't have the cognitive ability for language. It's too complex and abstract for them.
Similarly, they can manipulate a pool cue and even knock balls around a table with it potentially. But they can't actually understand the rules or play the game effectively, even though they can be taught rules of much more simple "games" like "press the red button and get a treat, press the blue button and get nothing."
Other primates already have the anatomy required for natural language more or less, namely arms and hands. Signed languages are as complete and expressive as spoken languages, and there is speculation [1] that spoken and signed language use the same underlying grammatical facility or "language organ".
Kinda OT, but this got me thinking about why human evolution has preferred spoken over signed language - why did spoken language evolve as the favourite mode when we already had perfectly good anatomy for signed language? Spoken language has some obvious disadvantages that I can think of:
* limited iconicity compared to sign
* not good for communicating while hunting
* less private
* speech production requires fine articulations and motor control, takes longer to learn, extends adolescence?
* "The positioning of the larynx deep in the throat, and the tongue far enough low and back to articulate a range of vowels, also compromised breathing and chewing. Presumably the communicative benefits outweighed the physiological costs." [2]
Spoken has some advantages over sign though:
* communication over distance
* sound-based iconicity/ possible
* can communicate with poor vision
* can communicate while performing manual tasks (this is probably the biggest one)
Maybe early humans used a combination of both depending on the situation, and as the abstraction capability of the brain increased, spoken became the (hearing) norm. Either way, it seems like anatomical explanations for language evolution aren't very useful. Female Cosmetic Coalitions[3] is an interesting theory from anthropology which relates evolution of natural language with in-group trust.
I think the "can communicate with poor vision" is the most important as its dark in about 50% of the day when sign language doesn't really work.
Not to mention that you first need to call the other's attention to start communicating with signs, possibly by making some sort of sound so they look at you.
The second most important benefit is (IMHO) that you can speak while you are focusing on something, e.g. waiting for the prey to come closer while everyone holds their weapons.
I would hypothesize that vocal speech is much faster and relatively effortless. Hunters still use sign language, so it has its place. For private speech people whisper or lipread.
If you try to getva child to talk, it takes about two years of arduous effort. To get a primate to talk, you would need to raise as your child, spending a few years in the process.
That parrot that talked, was raised in such a way.
So why can parrots be taught to speak? Of course they do not understand what they are saying but they can be trained to say words. Monkeys can be trained to do some pretty complex things in comparison to what a bird can do, it seems to me monkeys are smarter than birds. So it seems like there is some other part of the explanation that is not completely figured out here.
> "Monkeys can be trained to do some pretty complex things in comparison to what a bird can do, it seems to me monkeys are smarter than birds."
Crows are likely on par with chimps and dolphins for intelligence by creating their own tools in the wild and other intelligent behavior (language, facial recognition, passing on knowledge).
Parrots such as African Greys and cockatoos are right up there too with problem solving abilities. I know cockatoos can be trained to "pick locks" and then pass on the knowledge to other cockatoos.
I would guess it has to do with complex vocalizations and verbal language being of more importance to birds than most monkeys perhaps? Parrots and corvidaes (crows and jays) learn to understand and speak human words as an attempt to "fit in" and communicate with their group (in captivity that would be us). In the wild, they speak with the chirps and calls that other parrots and corvidaes make. For example, there is a type of parrot that gives a unique chirp to each of its children to refer to them like a name[1]. Crows and parrots can be miles apart at times so that's my guess for verbal language being of more importance to them than other forms of communication. They also have a dialect they speak when near each other and then the more common calls most of us hear when they're farther apart[2].
I know much more about birds than primates, so correct me if I'm wrong. Birds tend to be around people in captivity much more than monkeys, so guessing that may be part of the reason as well.
Good speculative fiction story: Extraterrestrial species of immortal primates visits Earth, deploys the substrate for Wernicke & Broca's areas into a species of speechless apes, to see the invention of Shakespeare.
People should use this recording to ask their partners to consent to marriage. It says, our union will be both creepy and scientific in a way that is usually difficult to convey.
