Re: Natural Language and Natural Selection

From: Stevan Harnad (
Date: Sun May 26 1996 - 17:50:11 BST

> From: "DONNA CRUMLEY" <>
> Date: Fri, 19 Apr 1996 11:20:42 GMT
> Is language a biological capacity or a cultural invention ( or both ) ?
> Human language is much more than speech, it is a system for
> representing knowledge that lies at the very core of human thought.
> ( Fromkin and Rodman, 1993. Cited in principles of Behavioural
> Neuroscience 1995 ). It is organised to say things about things. Even
> single word utterances are usually understood as propositions. For
> example, if a child says the word " sweet " we take that to be the
> expression of the wish, " Give me some sweets. " But we usually speak
> in sentances , or sentance fragments, that are full propositions, in
> which information about things is sought or given.

Everyone: Please remember to use a spell-checker before submitting a
paper, whether by email or in paper...

> Language is an intergral part of every human society. It is one
> of the most complex systems a person ever learns, but children in a
> wide range of different enviroments learn to use and understand
> language in a relitively short period. The issue of language and
> whether it is a biologically based factor or a cultural invention is
> a very complex one which has caused a lot of disscussion and
> argument.
> The first part of this essay will concentrate on views put
> forward in favour of language being a biological capacity. Pinker for
> example believes that the ability to use a natural language belongs
> more to the study of human biology than to culture. However, one of
> the main proponents of this view is Chomsky. He proposed that the
> human nervous system contains a mental structure that includes an
> innate concept of human language.

First, the innate structure is UG, not a "concept of human language."
Second, Chomsky didn't propose it; he concluded it from the results
of his theoretical success in explaining the data on our grammatical

> He believes that certain universal
> features common to all languages ( verbs for example ) are innate.
> His view is that language is an abstract system of rules which cannot
> be learned by traditional learning principles.

Grammar (and some aspects of phonology) are the only cases that
linguists have investigated. There's no reason to think that
volcabulary, for example, is innate and unlearnable.

> The input provided by
> society to children is so fragmented and incomplete that the
> enviroment input alone cannot account for the amazing feat of
> language. Children only receive a small number of examples of the
> wide range of complex structures that language is capeable of
> expressing. This is what Chomsky called the Poverty of the Stimulus.

They only receive a small number of examples, and those examples are all
positive; the child also does not make UG errors, so does not produce
negative examples either, for anyone to correct.

> He also suggests that we must ' know ' the grammar of our language
> so that we can work out the relationship between words in any
> sentance we hear. By working out these relationships we can decide
> what the sentence means. For example, we can recognise that the
> sentence " Beautiful thoughts eat loudly " is grammatically correct
> even if it is nonsense, whereas the sentence " thoughts loudly
> beautiful eat " is nonsense and ungrammatical.

At the time, though, Chomsky thought that meaning and syntax were
independent modules; it is no longer clear whether the theory still
implies this.

> In order to capture
> all the subtleties and complexities of language, Chomsky has
> suggested that language has to be analysed at a number of different
> levels. ( For example, surface and deep structures ). In addition
> there are also different components of language, syntax is more or
> less grammar, phonology concerns the actual sounds of languguage and
> the rules governing their use and semantics concerns the meaning of a
> sentence. Chomsky's rules have been criticised in the sense that they
> produce perfect grammatical sentences, whereas humans do not.

But humans can tell whether or not the sentences are gramatical, and
that's what Chomsky was trying to explain. Moreover, imperfect as they
are, the sentences people produce do not systematically violate UG
(though they may do so sometimes by accident).

> Other evidence in favour of language being a biological capacity
> is that human beings learn far more easily and quickly during a
> certain period i.e. infancy to puberty. ( Lennenberg 1967. Cited in
> Child Psychology. A contemporary viewpoint 4th edition, Heatherington
> and Parke ). The type of sounds humans make also give evidence that
> language is a biological capacity . All languages use only a limited
> sample of vocal sounds of all the possible sounds humans can make;
> for example no human language makes use of snorting or clapping
> sounds.

The evidence here is weaker: It's not clear that we couldn't use other
sounds if need be. The only limits are what our larynx and mouth can
produce (and our ears can hear); and even then there is the sign
language of the deaf, which is also a language...

> Other evidence that humans are developed with an innate ability to
> use language can be seen in patients who have suffered from brain
> damage. The left hemisphere of the brain has a dominance where
> language is concerned. When this part of the brain is damaged
> language and speech are very often affected. Illnesses such as Anomic
> aphasia often occour. Anomic aphasia is characterised by difficulties
> in finding the appropriate words in speech. For example, a person
> suffering from it knows that a clock is for telling time, but they
> can't quite grasp the vocabulary that it is in fact a clock. Anomic
> aphasia may be produced by damage to any part of the cortical
> language system and many other cortical areas as well. The very fact
> that language is effected by damage to the human brain is strong
> evidence to suggest that language is a biological capacity.

Well, even learned skills have a brain basis, and could be disturbed or
lost because of a brain injury. The sense of "biological" here is more
"inborn," because even a Skinnerian operant reponse is "biological" in
that it is affected by brain damage. (The wooly thinking here is
probably not your fault, Donna!)

> Darwin's theory of natural selection has led to studies relating
> language to a biological capacity. Pinker and Bloom for example
> outline how natural selection can be applied to language. The natural
> selection argument suggests that the only plausible explanation for
> the criterion of near ' perfect ' organs is by ' adaptive
> complexity '. Where many interacting parts of a system arrange
> themselves to fulfill a specific function. The eye is a perfect
> adaption for visual imagery and could only have occoured through a
> process of natural selection , those who did not need the function
> would not develop an eye. Pinker argues that if natural selection can
> explain the complex design of the eye then it can also explain the
> complex design system of language; which indicates that langugage is
> a biological capicity.

But the evolution of the eye, and its evolutionary advantages as well as
the constraints influencing it (e.g., the physics of light) are much
more straightforward than the evolution of UG: What advantage did it
confer over, say, simpler alternatives? How did it even begin to be
shaped by evolution, let alone arrive at its final, complex structure?
For the eye, there are answers to these questions; for UG, not.

> The degree to which a biological component can be said to be
> involved in the aqusition of language, and how specific this innate
> component is, are the subject of much dispute. Linguistics provides a
> much needed theoretical framework for investigating the language
> learning of children and techniques for dissecting what has to be
> learned and what has been learned at different stages of development.
> Those who take the view that language is a cultural invention may
> hold some answers regarding this framework.

The foregoing paragraph was rather vague...

> There is evidence to suggest that language is more a cultural
> invention than a biological capacity. Skinner comes into this
> category with his learning principles. According to Skinner the
> parent first selectively reinforces those parts of the child's
> babbling sounds which are most like adult speech, therefore
> increasing the number of times these sounds are made by infants.
> Parents reinforce sounds until they become more and more like adult
> speech.

What about the poverty of the stimulus, then?

> Another view within this field is that children learn through
> imitation i.e. The child picks up words, phrases and sentences
> directly by imitation and then through reinforcement and
> generalization the child learns when it is appropriate to use and
> combine these responces. Skinner also puts forward an arguement
> regarding rewards and punishmebt. This is what he terms ' Operant
> Conditioning '. A child acts in order to get rewards, for example if
> a child wants a yogourt, then they will say yogourt and receive a
> yogourt as a reward. Children do not like to be punished, so they
> increase their language ability by saying things correctly and being
> rewarded.
> On the surface the above ideas seem reasonable, but they have
> come under alot of scrutiny. One strong criticism is that the number
> of specific stimulus responce connections that would be necessary to
> even begin to explain language is so enormous that there would not be
> enough time to aquire these connections in a whole life time, not to
> mention a few short years. Another argument is that parents often
> reward children for grammatically incorrect sentences.

No one knows how to do the arithmetic for the number of connections, so
those are just guesses. But what about the poverty of the stimulus? the
absence of negative examples? To imitate a pattern, you need to try it
out and see if it's right. Chlidren never get UG wrong...

> Piaget holds some ideas in favour of language being a cultural
> invention. He proposed that language development grows out of
> changing cognitive processes of the child which, in turn reflects the
> changing nature between the child and his / her enviroment. He
> believed that many of the skills that children will utilise in their
> language are mastered in a non-linguistic manner during the first few
> years of life. In his view a child only learns to speak when it's
> cognitive development has reached a particular level. In short he
> believed that language is simply a reflection of a child's level of
> intellegence. In this way it could be argued that language is a
> cultural invention, because it is only by interaction with a child's
> enviroment that they are able to use language. Vygotski also believes
> that language holds it's roots in social interactions, therefore
> being a cultural invention.

So how does that square with what Chomsky found?

> It is very difficult to make a dividing line in the question of
> whether language is biological capacity or a cultural invention. It
> is more fair to suggest that both of these factors have an influence
> on language. The interactionist view of language is a perfect
> example. They believe that human beings are biologically prepared for
> learning to speak, yet at the same time they believe that language is
> learned in the context of spoken language. They are concerned with
> BOTH the biological and enviromental ( cultural ) factors in language
> development.

In reflecting on this question you need to take language apart a bit
more analytically: Grammar and some of phonology looks as if it is
inborn; vocabulary probably is not. Nor is the "style-grammar" of
particular languages (as opposed to UG).

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