Download Language universality idea tested with biology method

14 April 2011 Last updated at 22:24 GMT
Language universality idea tested with biology method
By Jason Palmer Science and technology reporter, BBC News
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 study challenges the idea that the "language
centres" of our brains are the sole driver of
language
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."
Family trees
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: IndoEuropean, 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".
The methods use inference in a
similar way to Mendel's studies of pea
plants
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."
http://www.bbc.co.uk/news/science-environment-13049700