Babel's Dawn

Chomsky's Theory of Language Origins

Noam Chomsky's interview on language with Ali G. Proof that Chomsky can suffer fools... well, if not gladly, at least gently.

The founder of modern linguistics, Noam Chomsky, was famous for decades for his dismissal of interest in the evolution of language. In recent years he has moderated his position and in a lecture recently made available on line (here, registration required) he outlines his scenario for how language evolved. It is about as different from the account being developed on this blog as a theory can be, making it of keen interest because it forces me to ask whether I have gone hopelessly astray and should change course quite sharply.

Humanity's Pump

East Africa's Rift Valley is familiar to many travelers who find a series of lakes beneath the rift escarpment. Over the ages many such lakes have come and gone, forcing the residents of the area to make do with things as they were during their short lifetimes.

At last I’ve been shown an evolutionary reason for developing the ability to say an infinite variety of things, thanks to the current (November) special issue of the Journal of Human Evolution devoted to the African climate where the human line of descent emerged. (Table of contents here) It is a great issue, likely to have a revolutionary impact on our understanding of the conditions that gave rise to Homo. In particular, adaptation to savanna grasslands appears to have been a much later pressure than we have supposed.

In one of the early posts on this blog I discussed the possibility that humans evolved along lake shores instead of out on the open savanna (see post). Now that idea is looking even better.

Visitors to East Africa find a very mixed terrain of desert, wetland, grassland, and forest spread across mountain ranges, vast flat spaces, the complicated Rift Valley faults, and numerous volcanic peaks. Ten million years ago, however, it was a relatively flat terrain covered with rainforest. Humans evolved in this land while the terrain itself was undergoing a series of great transformations; climate-wise it was the best of times, it was the worst of times.

The Two-Stranded Timeline

Human DNA combines two contradictory tendencies: Darwinian selfishness, and Franklinesque cooperativeness. Combining the two threads took time.

The last several posts on this blog have pointed the search for speech’s evolutionary origins in a new direction. Instead of looking for the appearance of a linguistic breakthrough (such as the first word), we should be looking for a more general breakthrough to a culturally-dependent community. So I thought I would re-orient the blog by posting a revised time line noting the likely milestones the emergency of speech.

Avoiding the Devil

Serious temptation in the science world comes not from sex or food, but from ideas that look too luscious to pass by.

Einstein used to imagine interesting solutions to old puzzles all the time, but upon investigation they would come apart. He would joke about how “the devil” had him going for a few days, before he got wise and gave it up. The past two posts have discussed a radical paper by a philosopher, Don Ross, in the September issue of Language Sciences (paper here).  It turns out that many long-standing puzzles can be explained if we accept Ross’s solution, but many old ideas and trusted observations seem to argue against it.  So, has the devil been giving the blog a run for its money the past few weeks?

For this blog the key points of interest in Ross’s paper are:

• In humans there is a disconnect between sensory input and motor output that makes our actions uncertain.
• The solution to this disconnect is the creation of a culture (virtual and real artifacts) that can cue our behavior and orient us toward the world.
• Language is the foremost feature of this cultural solution.

If this idea is not a devil’s joke, we are in for many more upheavals of thought. Neither Noam Chomsky’s metaphysics nor Stephen Pinker’s psychology can endure if this alternative account takes hold. On the other hand, Ross’s proposal remains theoretical and could be a will-o-the-wisp. It must be tested.

A New Suspect in an Old Case

The spirit (I hope) of this blog.

When I was a college freshman in St. Louis three friends of mine went downtown to see a movie. They were attacked by a mugger who came at them wielding a pipe. Two of my friends began to flee; the third one (a giant of six foot four who was used to standing his ground) stood still in surprise. One of the two others called out, “Run, Sheidler,” and Sheidler began to run. Speech had saved him from serious harm. I haven’t thought about that story in decades, but it comes back to me now as an example of how speech can substitute for reflex.

Last week’s post on this blog reported on a paper by a philosopher, Don Ross,  in the September issue of Language Sciences (paper here) that suggests, to me at least, a solution to the question of what had to happen to make speech possible. Ross, basing his thought on the work of Australian philosopher Kim Sterelny, proposes what I called “abstract attention” and he calls “decoupled representation.” Whatever the term used, it refers to a break in the connection between stimulus and response. If you prefer computational terms, it’s a divorce between input and output.

Normally, such a break would be a personal disaster. A leopard that recognizes a baboon and does not immediately chase it, or a baboon that recognizes a leopard and does not immediately flee is in trouble, desperate trouble. Whatever genetic oddity led to the slowed behavior would be rapidly deselected from the gene pool. But the human line turned it into something triumphant, a species that lives in a community shaped by a culture. Language, in this view, is not a useful tool whose benefits are so great and obvious that we can only wonder why no other species evolved it. Language becomes the evolutionary solution to a normally ruinous predicament. Without speech Big Dave Sheidler’s abstract attention would have been a disaster; with it he had something to laugh about.

Some Answers at Last

The Structure of Speech. It is obvious that speech requires a speaker, a listener, and a topic. But each of these things seems unlikely to evolve. Why should either one care about a neutral topic? Why should the listener care what the speaker has to say? Why should the speaker reveal what is on his mind?

Ape language has been back in the news. Washoe, the first chimp to learn any sign-language words, has died. (NY Times obit here). And eSkeptic has published a piece arguing that primates don’t have language because none of them use or really understand syntax (essay here). But the syntax argument is looking a little off-point these days, especially after a path-breaking paper by Don Ross in the September issue of Language Sciences (abstract here; paper here). The essay brings progress to some of the most persistent questions that have come up on this blog.

Do Genes Bring Up the Rear?

The Masai of central Kenya and Tanzania use tones to distinguish between the subject and object of a sentence.

My previous two posts were about genes and language. One (about the FoxP2 gene, here) was about the kind of thing we take for granted these days; a gene has been found that causes speaking problems when it mutates. If you have the mutation, you have a problem articulating properly. This process makes easy sense to us because we expect genes to affect the individuals who carry them. The other post (about tonal language, here ) reported the much more surprising idea that individual behavior can be affected by the genes of an entire population. Thus, for example, if you live among a people where the ancestral  variety of the Microcephalin gene  predominates, you probably speak a tonal language, even though you have a more recent variety of the gene. Meanwhile, another person with that gene who lives among people where the ancestral variety is rare, probably does not speak a tonal language. I have the feeling that this discovery is one of those things, like Robinson Crusoe observing a footprint, that changes many expectations. The Dediu-Ladd paper on the relation between tones and genes (see here) calls for a new way of thinking about thinking. The nature-nurture discussion just took a new turn.

Was the First Language Tonal?

I want to expand on last week’s post (about the FoxP2 gene) by considering another piece of research about genetics. A paper  published last May by Dan Dediu and Robert Ladd of the University of Edinburgh (author’s summary available on-line here, complete with links to the full article) argues that a population’s “genetic structure” can exert an influence on the features of the language spoken by that population. Specifically, they demonstrate that populations that speak tonal languages have one sort of genetic structure, while non-tonal populations have another.

Tonal languages are those like Chinese and many African languages that distinguish between words by altering their pitch. Non-tonal languages use consonants and vowels. Tonal languages use consonants, vowels, and pitch. A non-tonal language like English distinguishes between words by changing a vowel, a consonant, or both. Thus, we distinguish between do and shoe by keeping the vowel sound but altering the consonant. Grammatical distinctions can be made by the same changes. The Latin amas (you love) amat (he loves) depends on a change from s to t to make a grammatical distinction. In Swahili the change from k to v can distinguish between singular and plural forms: kitabu (book), vitabu (books). Tonal languages have three ways to change a word; thus, Chinese can keep the same consonant-vowel pattern do and do, and yet still distinguish between the two words by speaking one with a high pitch and the other with a low pitch. Tones can also make grammatical distinctions. The Masai language, for example, says the equivalent of saw he she, no matter who did the seeing and who was seen. Speakers use tone to indicate which word is the object and which the subject. Personally, I’ve always been glad I never had to learn a tonal language.

The Dediu and Ladd paper says there is genetic difference between populations that speak tonal languages and those that do not. For this blog, it raises the question of what kind of language was originally spoken, a tonal or non-tonal language. More generally, it suggests a new way of thinking about the process of speech origins.

The Co-evolution of Speech and Speakers

Forbidden Planet's Robby the Robot. What sort of language would a race of them evolve?

Two kinds of evolution tangle thinking about the origins of speech. The first is biological evolution that adapted our bodies to the task of speaking. Then there is the linguistic evolution that shaped the languages we speak. If we define evolution vaguely as change over time, we can agree that both bodies and languages evolve. But if we speak more precisely and say that evolution refers to the Darwinian processes that produce change, can we also say that language really evolves? A recent report in the journal Cognitive Processing says yes, linguistic evolution is more than just analogous to biological evolution; it uses Darwinian processes. If the report’s authors are correct, two evolutionary processes were triggered when people began to speak. One adapted our bodies to speech, the other adapted speech to our community. The dual evolution is very much like the co-evolution of brain and language that Terrence Deacon proposed in his book The Symbolic Species.

What Came First?

Mmm. I see just what I want. Now. How do I tell the waiter?

Which came first, speech or gesture? That question comes up often in discussions of speech origins, but an article by Susan Goldin-Meadow in the current issue of Child Development (abstract here) suggests the question may be beside the point. Speech and gesture go together today and probably always have. Something else came first.