Re: Natural Language and Natural Selection

From: Liz Lee (
Date: Mon Apr 22 1996 - 13:10:57 BST

Is language a biological capacity or a cultural invention (or both)?

What is language? The general consensus seems to be that it is a
rule - based system, using arbitrary symbols to represent
information which is passed on to others who are able to receive,
and understand the same system. The fact that symbols are used is
relevant, this makes language distinct from mime which, although a
means of communication, depends on mimicry of gestures to convey
meaning, for instance making a "sad" face to show "sadness" is very
different from using the completely arbitrary word "sad" to do the
same. It is unique to the human world, with all human children
having acquired it by the age of six (Pinker, 1994), other animal
groups may have a means of communicating fear, amorous overtures,
aggression or the whereabouts of food, but that is the limit of
their ability. Humans are able to contemplate the past, speculate
about the future, discuss politics, counsel their kin, move an
audience to tears or make it rock with laughter by using a shared
language. This is possible even if verbal communication is
unavailable, as in the case of the deaf community using sign
language. This essay will look at the origins of language
acquisition, focussing on whether evolution can be credited with our
language abilities, or whether language was "invented" ( like
writing) to meet our cultural needs.

Biologically, we have been endowed with the detailed structures
required to be able to produce and receive a spoken language. The
vocal tract is shaped in a specific way, creating hollow cavities
for sound resonance, the lips, tongue and mouth are controlled at
will, the vocal cords produce sound by vibrating when air from our
lungs is expelled whilst "speaking". The human auditory system is
"tuned in" to the correct frequency to receive speech sounds.
Studies of newborns detail their "preference" for human speech over
other similar sounds, and their "conversation- like" interactions
with their mothers (Schaffer, 1978). Pinker (1994) suggests that
the development of the vocal tract has drawbacks, in that it
compromises breathing and swallowing, this implies there must have
been some evolutionary advantage in being able to speak. Areas of
the brain (Broca's and Wernicke's areas in particular), which are
associated with language but no other known cognitive processes,
have developed. Proof of this is seen when stroke sufferers may have
language, but no other cognitive, impairment, alternatively they
may have intellectual impairment with intact language ability
depending on the area of brain tissue affected. However Bates (1994)
 argues against domain specificity pointing out that children who
suffer large brain lesions in "language" zones still go onto develop
a normal language ability - albeit after some delay. Pinker and
Bloom, (1990) suggest a "critical period" for language acquisition
which renders language acquisition difficult after a certain period.
  The structures required for language are innate, they are common
to all humans and are unaffected by environment, but the cultural
setting is important in language acquisition and will be discussed
later. Pinker and Bloom deal with the question of whether, given
that we share a common ancestor, (approx. 6 million years ago), one
would expect similar language developments in apes, (citing Bates,
Greenfield and Lieberman) by arguing that since our paths diverged,
apes have followed their own pattern of selective adaptation which
need not resemble ours. He cites cases where apes (chimpanzees)
have been taught a limited signing vocabulary after many teaching
sessions, and compares this to the ease with which human children
learn their own language, without any obvious instruction. So there
being no evidence of language structures in other primates is not a
bar to human language development being designed by natural
selection. There was, it seems, some advantage to be gained, at
some point in our evolution, by being able to pass on information to
others. There is another view, Noam Chomsky and Steven Gould ( cited
in Pinker and Bloom, 1990) suggest that language may have evolved
as a result of some other development or because of an overall
growth in brain size. What they are proposing is that the specific
adaptations which have occurred, allowing us to develop and use
language, were a by-product or "evolutionary spandrel" which just
"happened" to be. This does not seem likely when compared to other
complex biological structures which have evolved with a specific
function, the eye for instance. One reason for this idea was
Chomsky's belief that evolutionary changes are a long, gradual
process and as such a new ability (language) is unlikely to emerge.
A second reason is the presence of what he calls "universal
grammar" (UG), this is a grammatical pattern which is present in all
languages, and obeyed even by young children. Chomsky suggests that
obeying UG is an innate ability, but one which confers no
evolutionary advantage, and therefore cannot be the subject of
natural selection. But UG is one very small part of language and it
seems rash to dismiss the whole of language as a by-product for the
sake of one of it's less obvious constituents. The premise that UG
is always obeyed and so children are not exposed to these specific
grammatical errors ( the Poverty of the Stimulus) is argued
against by Pullum (1996 ), on the grounds that the rules
surrounding UG are regularly broken by adults in everyday language,
he gives examples from the "Wall Street Journal" and concludes that
rather having an innate language ability, children learn in a
data-driven way. Pinker and Bloom ( 1990 ) gave a more reasoned
argument against the spandrel idea, they suggest firstly that
evolutionary changes can, and do occur over relatively short time
spans, coupled with the facts that it requires only a small
advantage to initiate change, and there is no proof that language
has evolved on a random way. Secondly that there is an obvious
advantage to be had by being able to pass on knowledge to one's
offspring without them needing to experience incidents first hand.
They answer the UG question by suggesting that there is an advantage
to be had by using grammar in an exact way - it is essential to know
the intended meaning of a sentence in order to act appropriately,
for instance whether "the child fell over the dog that died" has
the same meaning as "the child fell over the dog and died" - which
of course it does not. So there is a good reason for having some
kind of inbuilt ability in place - to already know the code - this
reduces the chance of getting it wrong when the learning process

When, and why, did language evolve? Bates ( 1994 ) estimates that
language is a relatively recent cognitive development, approximately
30,000 years ago, although Pinker and Bloom point out that there is
fossil evidence of the presence of Broca's area 2 million years ago.
The emergence of language coincided with that of tool this and this
would seem to be relevant. Pinker (1994) proposes two reasons for
the evolution of language, firstly, our ancestors developed
knowledge both of technology (tool use) and the environment, and
second, co-operation between community members was significant.
Harnad (1995) suggests that language is used by a community to
classify their world, when referred to a hunter-gatherer existence,
it makes sense that passing on shared information about distances
travelled to obtain food supplies, or the location of poisonous
vegetation should enable those receiving, decoding, and acting on
the information to be better equipped than those who do not have
this information source. The better communicators were more likely
to produce offspring, (being well-nourished and able to keep away
from danger), and passed on this ability to future generations.
Pinker and Bloom (1990) note that humans have the ability to store
knowledge across generations, and that this is a "species -
specific and universal feature". An interesting, but less
compelling reason for language is covered by the Whorf hypothesis (
cited by Pinker and Bloom,1990, and Harnad, 1995). Whorf suggests
that language is just a way of labelling our thoughts, and that this
 influences our view of reality, the way things look to us depends
on how we name them, so each different language-speaking people will
look at the world differently. Pinker (1994 ) argues that this
cannot be the case, since babies are able to distinguish between
phonetics before they can understand the meaning of the sounds, and
questions whether they could learn a language without some relevant
structure in place first. Harnad (1995) goes further and suggests
that it is probably the other way round - our view of reality
influences our language. How is culture or environment involved?
Language has been shaped by culture, the particular language,
dialect, accent and lexicon we use is entirely due to the cultural
setting. Babies are able to make phonemic distinctions, which is as
well because these are culturally determined and it would be
disadvantageous for a child to be unable to differentiate between
the essential components of his or her language. There is well
documented evidence of the pattern of neural growth and destruction
in the fetus, newborn and child, the loss of brain cells in the
early years coincides with a rapid growth in nerve fibres. The
ability of a young child to learn any language effortlessly compares
favourably with the older child or adult trying to learn a second
language, it is not the learning of a new vocabulary which is hard
- there is no evidence that this ability reduces with age - but then
a language as stated earlier is a great deal more than just
individual words. But a culture without a language is unknown,
linguistic social competence is important in any culture, and the
language must be able to convey whatever meaning the speaker
chooses, it must also be readily understood by the recipient. In
conclusion, the evolution of language by natural selection seems a
reasonable proposal, whether or not the finer points in any language
are so readily explained is unproven, however there is no doubt that
the influence of the cultural setting is as important to the
language being used, as the ability to use the language itself.


Bates,E.( 1994). Modularity,Domain Specificity and the Development
of Language.

Harnad, S. (1995). The Origin of Words: A Psychophysical Hypothesis
in Durham, W and Velichkovsky B (Eds.) "Communicating Meaning:
Evolution and Development of Language. NJ: Erlbaum.

Pinker, S ( ). Language Acquisition. (Chapter for Gleitman, LR,
Lieberman, M and Osherson, DN.(Eds.) An Invitation to Cognitive
Science, 2nd Edition. Vol.1 Cambridge,MA: MIT Press.

Pinker, S and Bloom, P (1990) Natural language and natural
selection. Behavioral and Brain Sciences (1990) 13, 707-784.

Pullum, GK. (1996) Learnability,Hyperlearning and the Poverty of
Stimulus. Paper presented at the Parasession on Learnability, 22nd
Annual Meeting of the Berkeley Linguistics Society, Berkeley,
Calif., (1996).

Schaffer, R. (1978) Mothering. Fontana. London

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