The study challenges the idea that the “language centres” of our brains are the sole driver of language
A long-standing idea that human languages share universal features that are dictated by human brain structure has been cast into doubt.
A study reported in Nature has borrowed methods from evolutionary biology to trace the development of grammar in several language families.
The results suggest that features shared across language families evolved independently in each lineage.
The authors say cultural evolution, not the brain, drives language development.
At the heart of both studies is a method based on what are known as phylogenetic studies.
Lead author Michael Dunn, an evolutionary linguist at the Max Planck Institute for Psycholinguistics in the Netherlands, said the approach is akin to the study of pea plants by Gregor Mendel, which ultimately led to the idea of heritability of traits.
“By looking at variation amongst the descendant plants and knowing how they were related to each other, [Mendel] could work out the mechanisms that must govern that variation,” Dr Dunn explained to BBC News.
“He inferred the existence of some kind of information transfer just from knowing family trees and observing variation, and that’s exactly the same thing we’re doing.”
Modern phylogenetics studies look at variations in animals that are known to be related, and from those can work out when specific structures evolved.
For their studies, the team studied the characteristics of word order in four language families: Indo-European, Uto-Aztec, Bantu and Austronesian.
They considered whether what we call prepositions occur before or after a noun (“in the boat” versus “the boat in”) and how the word order of subject and object work out in either case (“I put the dog in the boat” versus “I the dog put the canoe in”).
The method starts by making use of well-established linguistic data on words and grammar within these language families, and building “family trees” of those languages.
“Once we have those trees we look at distribution of these different word order features over the descendant languages, and build evolutionary models for what’s most likely to produce the diversity that we observe in the world,” Dr Dunn said.
The models revealed that while different language structures in the family tree could be seen to evolve along the branches, just how and when they evolved depended on which branch they were on.
“We show that each of these language families evolves according to its own set of rules, not according to a universal set of rules,” Dr Dunn explained.
“That is inconsistent with the dominant ‘universality theories’ of grammar; it suggests rather that language is part of not a specialised module distinct from the rest of cognition, but more part of broad human cognitive skills.”
The paper asserts instead that “cultural evolution is the primary factor that determines linguistic structure, with the current state of a linguistic system shaping and constraining future states”.
However, co-author and evolutionary biologist Russell Gray of the University of Auckland stressed that the team was not pitting biology against culture in a mutually exclusive way.
“We’re not saying that biology is irrelevant – of course it’s not,” Professor Gray told BBC News.
“But the clumsy argument about an innate structure of the human mind imposing these kind of ‘universals’ that we’ve seen in cognitive science for such a long time just isn’t tenable.”
Steven Pinker, a cognitive scientist at Harvard University, called the work “an important and welcome study”.
However, Professor Pinker told BBC News that the finer details of the method need bearing out in order to more fully support their hypothesis that cultural boundaries drive the development of language more than biological limitations do.
“The [authors] suggest that the human mind has a tendency to generalise orderings across phrases of different types, which would not occur if the mind generated every phrase type with a unique and isolated rule.
“The tendency may be partial, and it may be elaborated in different ways in differently language families, but it needs an explanation in terms of the working of the mind of language speakers.”
By Jason PalmerScience and technology reporter, BBC News
Languages vary widely but not without limit. The central goal of linguistics is to describe the diversity of human languages and explain the constraints on that diversity. Generative linguists following Chomsky have claimed that linguistic diversity must be constrained by innate parameters that are set as a child learns a language1, 2. In contrast, other linguists following Greenberg have claimed that there are statistical tendencies for co-occurrence of traits reflecting universal systems biases3, 4, 5, rather than absolute constraints or parametric variation. Here we use computational phylogenetic methods to address the nature of constraints on linguistic diversity in an evolutionary framework6. First, contrary to the generative account of parameter setting, we show that the evolution of only a few word-order features of languages are strongly correlated. Second, contrary to the Greenbergian generalizations, we show that most observed functional dependencies between traits are lineage-specific rather than universal tendencies. These findings support the view that—at least with respect to word order—cultural evolution is the primary factor that determines linguistic structure, with the current state of a linguistic system shaping and constraining future states.
What’s the News: Noam Chomsky, look out: If language has any universal grammar, it’s hiding really well, conclude the authors of a recentNature study. The idea that all human languages share some underlying structure, regardless of where or when they evolved, an influential idea that nonetheless has drawn somecontroversy since Chomsky popularized it in the 1950s. One part of natural-grammar theory is the idea that certain word order rules (whether the verb or the noun goes first and whether a preposition goes before or after a noun, for example) will always associate together, regardless of which language they occur in.
But when cognitive scientists and a biologist teamed up to see whether there were shared patterns in word order across four large language families, they found almost none. A common cultural background, they found, was the best predictor for how a language orders words.
How the Heck:
- Applying biology techniques to linguistics, the team built an evolutionary tree of word order. They treated word order as a trait, just as biologists might treat eye color or hair color.
- They looked to see whether one word order rule was always connected with another, testing the Chomskian idea that rules associate in certain sets. Under this hypothesis, “the setting ‘heads first’ will cause a language both to place verbs before objects (‘kick the ball’), and prepositions before nouns (‘into the goal’),” the authors explain.
- Analyzing four large families that account for more than a third of the world’s languages (Austronesian, Indo-European, Bantu, and Uto-Aztecan), the team found 19 correlations between pairs of word rules. But only four of them appeared in more than one family, indicating that as far as word order is concerned, this aspect of universal grammar doesn’t seem to hold up.
Reference: Michael Dunn, Simon J. Greenhill, Stephen C. Levinson, Russell D. Gray. Evolved structure of language shows lineage-specific trends in word-order universals. Nature, 2011; doi:10.1038/nature09923
5 Responses to “Is Grammar More Cultural Than Universal? Study Challenges Chomsky’s Theory”
- 1. Linguist Says:
April 15th, 2011 at 6:19 pm
There *is* no “Chomskyan idea that rules associate in certain sets”, especially where the rules in question concern WORD order (rather than the more abstract structural relations that Chomsky and his colleagues do concern themselves with).
The study in Nature has literally nothing at all to do with anything Chomsky has argued for.
Now this article may be interesting for other reasons — see Mark Liberman’s thoughtful discussion today in Language Log, for example. But the anti-Chomsky spin placed on the article is just nuts (though it’s a good way to get publicity for a study on language). The results have logically nothing to do with Chomsky or with Universal grammar. As a linguist, I cringe at this sort of nonsense — especially since it seems to come around every year or so (Google “Piraha”, for example).
- 2. Anon Linguist Says:
April 16th, 2011 at 7:26 am
I think this study is attempting to falsify the existence of universal parameters. But Chomsky’s principles and parameters theory argues for *parametric variation*, which the study finds. Ergo this study is not falsifying anything Chomskian.
Also, reading the authors’ quotations, they seem to be on a mission to explain surface (not abstract) linguistic variation as “cultural”. But what is “cultural”? It means nothing. They also dismiss Pinkerian modularity of mind and suggest the mind is “far more complex” the modularity hypothesis assumes. How exactly? They do not explain.
A welcome study but I’m not impressed.
- 3. Stevan Harnad Says:
April 16th, 2011 at 1:32 pm
LINGUISTIC NON SEQUITURS
(1) The Dunn et al article in Nature is not about language evolution (in the Darwinian sense); it is about language history.
(2) Universal grammar (UG) is a complex set of rules, discovered by Chomsky and his co-workers. UG turns out to be universal (i.e., all known language are governed by its rules) and its rules turn out to be unlearnable on the basis of what the child says and hears, so they must be inborn in the human brain and genome.
(3) Although UG itself is universal, it has some free parameters that are set by learning. Word-order (subject-object vs. object-subject) is one of those learned parameters. The parameter-settings themselves differ for different language families, and are hence, of course, not universal, but cultural.
(4) Hence the Dunn et al results on the history of word-order are not, as claimed, refutations of UG.
Harnad, S. (2008) Why and How the Problem of the Evolution of Universal Grammar (UG) is Hard. Behavioral and Brain Sciences 31: 524-525 http://eprints.ecs.soton.ac.uk/15618/
- 4. Peter Says:
April 16th, 2011 at 8:28 pm
could you please direct us to a paper/book that *explicitly* lists *exactly* what is the “complex set of rules” of UG that Chomsky is claimed to have “discovered”? As far as I know, there is none. Note the stress on the words “explicit” and “exact”.
- 5. Linguist Says:
April 16th, 2011 at 10:03 pm
Harnad overstates his case. Linguistics is an active field in which there are many open questions. So there is no complete, explicit, exact set of rules out there that answers all our questions and solves all our problems in linguistics. Neither Chomsky nor any other linguist would claim otherwise.
But there are explicit,exact proposals about subdomains of UG: for example, Cinque’s theory (modified in a subsequent paper by the linguists Abels and Neeleman) of Greenberg’s “Universal 20″, which governs the order of adjectives, determiners (e.g. “the”, “a”, “this”), numerals and the noun in Noun Phrases across languages of every family. Googling for “universal 20″ and one of the names mentioned above will get you to those papers.
If you want a less technical book for non-specialists that tells you something about what has been discovered about language variation more generally, I recommend Mark Baker’s “Atoms of Language”. If you’re looking for someone’s explicit, exact computer program that models this kind of system across a broader domain, look at the work of Sandiway Fong among others. For an explicit model of the acquisition process in this vein, Charles Yang’s research is a good place to start.