koganbot | (Reply)

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I'm baffled by the responses here. Is there something about your posts that I'm not getting? Something about my post that you're not getting? Are you pushing the question away, or just warming up?

I already know that language is rare. What is not obvious is why it's rare. To put it another way, it is not obvious why other creatures that are social, can vocalize, and can communicate don't use sentences. They can generalize - food versus nonfood, potential predator versus not a potential predator - and they can learn new associations: ringing bell means someone's going to bring me meat, not only does smoke mean fire, "Fire!" means fire, etc.

Asking why language is rare doesn't seem to me equivalent to asking "Why doesn't anything other than a kangaroo look just like a kangaroo?"

It'd be more like asking, "Why, since so many species developed gliding capacity, and others use appendages to extend their jumps, only one developed flying capacity?" Except that lots developed flying capacity.

I have no horse in this race as to whether Deacon's or someone's competing theory is right; but he is saying something that I hadn't heard elsewhere, which I wrote in my post (and then elaborated on in the comments): 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.

And where he's going with his argument seems to be, though I haven't gotten there yet, that the ability to tie specific signs to specific other phenomena, if it comes too early in an infant's development, would interfere with learning to relate symbols to other symbols. So that humans are born relatively immature would be one thing that makes language learning possible. (Obviously this isn't the whole story.)

If Deacon is right, he's explained a lot rather simply and elegantly, without having to go "Here are the 467 factors that came together for human beings"; and you don't have to go from species to species to wonder why for each one it didn't come up with 368, or 914, or 311 factors that would have worked.