Why has language only evolved once?
Mar. 26th, 2010 01:25 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
koganbotI'm reading a book by Terrence W. Deacon called THE SYMBOLIC SPECIES: The Co-evolution of Language and the Brain that I pulled off the philosophy shelf at Barnes & Noble and then borrowed from the library, and I'm loving it. The author is unknown to me (which doesn't tell you anything about how well-regarded he might be; but a book that's on store shelves a decade after it was published is sure doing better than my book), I don't have the background to evaluate whether he's doing right by the information he's drawing on, and I don't know the linguistics discourse he's responding to so am only provisionally assuming he's right in his presentation of other people's ideas.
What I like is that he asks questions, and they seem like good questions, and it seems to make sense that he's asking them. Here's something that needs to be explained, he's saying, and he's saying that he doesn't like the explanations given so far, so he's going to come up with his own.
Deacon was talking to an elementary school class, and an eight-year-old asked him, "But don't other animals have their own languages?"
Deacon responded by explaining how human language is different from any other form of communication in its precision and its capacity to combine elements logically but with open-ended possibilities.
"Do animals just have SIMPLE languages?" the kid continued.
Deacon said that though animals have calls and such they have nothing like words, nouns, verbs, or sentences.
Another child asked, "Why not?"
And this stumped Deacon, who had no idea how to answer. So he poses a question in his preface: "Why are there no simple languages with simple forms of nouns, verbs, and sentences?"
This leads to another question: why has language only evolved once? If animal communication is a primitive or less-developed form of human language, the only difference being capacity, it would seem preposterous that over 650 million years no other creature similarly developed the use of words, nouns, verbs, and sentences, even in simple form, and that no current creatures have anything like sentences. (I'm not sure that this is altogether true, this last bit, but my guess is that it's true enough.) Human language is an anomaly that has to be explained. Deacon uses the analogy of fur and porcupine quills; it would be ludicrous to say that all fur was a primitive form of porcupine quills.
And here he puts forth a hypothesis that I wasn't expecting. He suggests that to acquire human language would conflict with some normally advantageous feature of animal communication; that to develop or (if you're a pet, say) learn a language would require something analogous to the unlearning of useful communication skills and their replacement by others. So it would be rare for evolution to select for the loss of adaptive communication skills, even though these skills interfere with the development of something potentially more adaptive: language.
So that's where Deacon starts. He goes on to try to explain what we've got that animals don't - basically, our way of relating words to other words - and what interferes with this, which is the ability to tie specific signs to specific other phenomena, an ability that animals do have. This section of the text is murky, but if I understand Deacon right, the "unlearning" involves a shift in attention from what we've actually experienced as associating with something else and replacing it with knowledge of what can associate with something else, whether we've seen it or not.
Deacon doesn't like the concept of Universal Grammar, that our grammatic ability is built into our brains, because he doesn't think it explains anything. He says that it tells us that we have the skill, but it doesn't explain how we got it. He tries to develop a more useful explanation. I don't have time to post about it now, but it involves both something like "unlearning" (more accurately, "not learning too soon") and the idea that languages evolve much faster than human brains do, and that the basic features of language must evolve so as to be learnable by toddlers, so in effect toddler brains are the instrument of natural selection for the basics of human language.
I'm about a third of the way through.
What I like is that he asks questions, and they seem like good questions, and it seems to make sense that he's asking them. Here's something that needs to be explained, he's saying, and he's saying that he doesn't like the explanations given so far, so he's going to come up with his own.
Deacon was talking to an elementary school class, and an eight-year-old asked him, "But don't other animals have their own languages?"
Deacon responded by explaining how human language is different from any other form of communication in its precision and its capacity to combine elements logically but with open-ended possibilities.
"Do animals just have SIMPLE languages?" the kid continued.
Deacon said that though animals have calls and such they have nothing like words, nouns, verbs, or sentences.
Another child asked, "Why not?"
And this stumped Deacon, who had no idea how to answer. So he poses a question in his preface: "Why are there no simple languages with simple forms of nouns, verbs, and sentences?"
This leads to another question: why has language only evolved once? If animal communication is a primitive or less-developed form of human language, the only difference being capacity, it would seem preposterous that over 650 million years no other creature similarly developed the use of words, nouns, verbs, and sentences, even in simple form, and that no current creatures have anything like sentences. (I'm not sure that this is altogether true, this last bit, but my guess is that it's true enough.) Human language is an anomaly that has to be explained. Deacon uses the analogy of fur and porcupine quills; it would be ludicrous to say that all fur was a primitive form of porcupine quills.
And here he puts forth a hypothesis that I wasn't expecting. He suggests that to acquire human language would conflict with some normally advantageous feature of animal communication; that to develop or (if you're a pet, say) learn a language would require something analogous to the unlearning of useful communication skills and their replacement by others. So it would be rare for evolution to select for the loss of adaptive communication skills, even though these skills interfere with the development of something potentially more adaptive: language.
So that's where Deacon starts. He goes on to try to explain what we've got that animals don't - basically, our way of relating words to other words - and what interferes with this, which is the ability to tie specific signs to specific other phenomena, an ability that animals do have. This section of the text is murky, but if I understand Deacon right, the "unlearning" involves a shift in attention from what we've actually experienced as associating with something else and replacing it with knowledge of what can associate with something else, whether we've seen it or not.
Deacon doesn't like the concept of Universal Grammar, that our grammatic ability is built into our brains, because he doesn't think it explains anything. He says that it tells us that we have the skill, but it doesn't explain how we got it. He tries to develop a more useful explanation. I don't have time to post about it now, but it involves both something like "unlearning" (more accurately, "not learning too soon") and the idea that languages evolve much faster than human brains do, and that the basic features of language must evolve so as to be learnable by toddlers, so in effect toddler brains are the instrument of natural selection for the basics of human language.
I'm about a third of the way through.
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no subject
Date: 2010-03-28 07:21 pm (UTC)it's the convoluted path (simple to follow, but at some point the unobvious choice leads to the jackpot) vs the complex path (an obvious choice with a lot of ground to cover and problems to solve.
so it's an interesting alternative, but the complexity threshold or 'only one tallest tree' argument still seems valid. and cos hom sap is singular in so very many features, it's 'easy' to suggest than any of these, or combiantion thereof is also necessary.
again, so many lovely theories. what i like are all the confliciting theories about what was the primary 'driver'. My favourites tend to be about forming larger social groups for some reason. the resource-based rewards (nat selection gold!) for organised behaviours leading to larger groups, leading to strategies to cope with them, that lead to the mental faculties that form the basis of language. language as grooming/social-control.
<arthur c clarke>perhaps i like these because it suggests that in the super-connected age of t'internet developing new strategies for such social intereactions will lead us somewhere else again.</arthur c clarke>
no subject
Date: 2010-03-28 07:22 pm (UTC)for some reason.no subject
Date: 2010-03-28 09:36 pm (UTC)Since Deacon is practically the only one I've read on the subject I can't really say he's doing something that no one else is doing, but by asking the question in the negative - why didn't other species develop language? - he's finding a different way into the question. That is, he's asking, "What inhibited other creatures from developing nouns and verbs and sentences and the like?" So he's not looking so much for a driver but an inhibitor. And this means he doesn't have to face questions like, "Why isn't forming large social groups a driver for a whole bunch of other species as well?" Of course, Deacon would have to answer the question, "Why is dropping the inhibitor so rare that only humans dropped it?" But there's at least a potentially logical answer to that one: "Because the inhibitor is really really really adaptive." So dropping the inhibitor is rare, but once it is dropped a species can then be open to various drivers.
I think one reason Deacon likes his own argument is that to some extent he's using it to kill two birds with one stone. A second question goes, how does a helpless, incompetent creature with a minuscule attention span and little impulse control - a human infant - master something so complex as a language at such a young age? I haven't really gotten to Deacon's answer, so I don't want to misrepresent the guy, but he seems as if he's going to intertwine his answer to this question and his answer to what opened up the species to evolve language.