I dig linguistics, and I dig HBD, so how do you join them both? I've had this idea for some time now, but I hadn't written about it lest some guy stole it and wrote a book before I did.
It seems I'll have to give up on that, as science is fast catching up with my awesome blog (see, I just pulled a Half Sigma here). Razib Khan quotes a recent study in Northern Australia that documents how some Abo kids came up with a new language just for the kicks. It fast became cool, and now the young kids of the tribe have a different language from their elders. As it looks it's a fully new language, with some grammar changes too, not just a bunch of jargon to fool their parents so they can avoid being eaten. A smart guy in Razib's Twitter also linked to an experimental study where they put people to compete in a game, and prompted to develop their own secret speech, which they did.
When you ask a layman they'll tell you that languages are to communicate. But that's patently false, if we wanted to optimize communication we'd all speak the same language. And languages wouldn't change over time. What the common theory is lacking is just a simple modifier. Languages are to communicate within the group. In fact this little modifier explains most of the mysteries of human psychology. Happiness correlates with income within the group. People are naturally cooperative within the group. Take the modifier away and you get the Cathedral.
Many academic theories about language posit that language evolve to aid better coordination, say for hunters. You go left, I go right, I throw the first spear, etc. Chimps seem to be able to coordinate without speaking, but it sounds reasonable that talking does help coordinate better. But if the idea is to be able to coordinate hunters, then why are men worse at language than women? Women do 70% of the talking, and it's mostly inane gossip. It has extremely little information density. Woman conversation is most of the time a status confirmation task, all they do is say get a group, say something and listen carefully to the tone of voice of all the participants, to check what everyone thinks of each other. If the mother hen suddenly is rude to you, well you know you're in trouble. You better find ways to raise your status or undermine hers. I taught a girlfriend that all her speech was an unconscious status confirmation task, and that she should stop caring as she will always be high status in my eyes. She never nagged me again.
For all I know language did start as a way for men to coordinate hunts better, but over time it's obvious that it evolution found other uses for it. Language itself is a big, a huge shibboleth, a simple way of knowing which tribe people belong to. Babies stop telling apart sounds not used in their native language by 10 months, before they even start talking themselves. And the ability to properly learn new phonemes dies permanently after age 10. With years of effort you can learn to communicate in a foreign language, but your accent will always give you away. And that's being lucky, most people just don't have the capability. And of those who do, a big majority are women, whose tribal membership is always tenuous. After all they never knew when they would be exchanged to a different tribe, or kidnapped and taken away.
A big puzzle of linguistics has always been the relationship between languages. Why are some language families so big, and others so small. One big language family extends from Ireland to Bengal. Yet dozens of different languages of 4 unrelated language families linger in close proximity in Southwest China. , with hundreds of languages of a dozen families. And those in the know say that most family groupings are very suspect.
Why don't the Papuans get their shit together and talk the same language? Because they don't want to. For thousands of years they have had no need of talking with the neighboring tribe. The neighbors were there to raid, kill, and occasional cannibalistic feast. Austronesian languages are famously extensive, from Hawaii to Madagascar. Yet the Philippines or Borneo are a patchwork of small tribal languages which are not intelligible by the nearby villages. It surely has something to do with the fact that every year, the able bodied males of a given village would raid the neighboring tribe, cut their heads off and bring them home as a trophy.
Farming changed the normal dynamics of tribal speech, with cooperation forced top down to vast masses of people engaged in farming and trading. First you had tens of thousands of people speaking the same language. Then millions. But massive, empire-wide koinés are tied to their empires, and always die and fragment. Ancient Greek died, Latin fragmented, as did Tang Chinese. The Middle Ages brought regional dialects, mostly sharing local market areas, the Enlightenment chose one dialect and artificially transformed it in the national tongue.
The ideology behind national tongues, nationalism, is dead, but national tongues are still around. Of course they are far too useful, and they are too strongly linked to the nation states who created them. But in the same way that the nation state is slowly losing relevance, so national languages are fading too. 50 years ago you would never have listened a regional accent on national TV, today the BBC makes a point of casting Scottish scientists for their documentaries. Italian dialects are making a comeback. Even in Japan a big part of movies are voiced in regional dialects, some quite obscure. All while every country on earth is putting ever more resources into English education.
If languages were to communicate, we would have an English speaking world in no time. Instead what we will have is a global English speaking elite, lording over masses speaking bad English to their masters, and revived regional dialects to themselves. Given Google Translate and PRISM, it wouldn't surprise me if vernacular writing dies out, with most speech being done in untranslatable dialect, and writing done in English. A massive Hong Kong style diglossia. It might be the only feasible resistance against what's coming.