Resources for Communication Problems

Monday, March 3, 2008



撰寫人:4856 李海琪

The pages227 ~ 230

Language in the light of evolution and genetics



We tell our children that the cow says “moo,” the lamb says “bah,” and the rooster says “cock-a-doodle-doo.” Most animals around us seem to “say” something, and there is a temptation to assume that they are “communicating”; but how, what. And to whom these animals “speak” are questions to which there are but vague answers. Most vertebrate species emit some kind of acoustics signal, and the sensory receptors of each species are sensitive to the broadcasts of their own kind. The ubiquity of this phenomenon suggests that some biological functions are the same for all species—in fact. There is good evidence against this. An acoustic broadcast may serve to warn territorial intruders, to call the young, to transfer information; it may function to strengthen social cohesion in large groups or to prevent the breaking up of single couples only; it may have the effect of arousing or of lulling; it may be directed at members of other species, at members of the same species, at only certain individuals, or only to the self, as in echo-navigation.


Animal communication does not merely fascinate us as a zoological phenomenon; it also encourages us to believe that appropriate comparative studies will reveal the origin of human communication. The rationale here is approximately this: since Darwin has shown that man is not the product of special creation but that he descended from more primitive animal forms, neither his structure nor his behavior are special creations. His forms of communication must have descended from primitive animal forms of communication, and a study of the latter is likely to disclose that there is indeed a straight line of evolution of this feature. This type of reasoning we shall call the continuity theory of language development. I do not agree with it, and the first part of the chapter will be devoted to a critical analysis. I will then propose a discontinuity theory and show that this is not only biologically acceptable but, in fact, more in line with present theories in developmental biology than the former type theory (Roe and Simpson, 1958; Simpson, 1949; Haldane, 1949; Rensch, 1954).


(1) Continuity Theory A: Straight Line Evolution of Language With Only Quantitative Changes


This type of theory rests on the belief that there is no essential difference between man’s language and the communication of lower forms. Man’s noises just sound different, and his repertoire of messages is merely much large than that of animals, presumably due to a quantitative increase in nonspecific intelligence. Theorists of this persuasion might picture the development of communication systems in the animal world as a straight road towards language such as shown in Fig. 6.1, with various animal communication systems as early way-stations. Human language is thought to be much more advanced, perhaps by virtue of some kind of proliferation of elements (more memory units; or more classification devices; or more computing elements). 


It can be only this kind of implicit belief that encourages investigators to count the number of words in the language of gibbons, to look for phonemes in the vocalizations of monkeys or songs of birds, or to collect the morphemes in the communication systems of bees and ants. In many other instances no such explicit endeavors are stated, but the under-lying faith appears to be the same since much time and effort is spent teaching parrots, dolphins, or chimpanzee infants to speak English. The rather wide-spread belief that many animals have a language of a very primitive and limited kind ( or that the animal pupils of English instruction can enter the first stage of language acquisition) is easily refuted by a comparison with man’s beginnings in language, discussed in Chapter Seven.


I. Limitations on inferences from animal comparison

FIG. 6.1. Diagram of a “straight-line” evolution; numbers indicate traits of various species thought to be direct antecedents of 5.

6.1. "直線" 的演化圖;數字代表不同物種在順序5之前的特徵

At the root of the idea that human language is merely quantitatively different from animal “language” is the idea that all animals have something that might be called “nonspecific intelligence,” but that man has much more of this endowment and that intellectual potential happens to be useful in the elaboration of a universal biological need for communication. Animals are thought to be unable to learn to understand English because of an insufficiency of this intellectual capacity. There are grave difficulties with this reasoning.


Intelligence or intellectual capacity are difficult to define in the context of general zoology. Insofar as intelligence is a measurable property within our own species (and there are those who have their doubts about this), we have seen (Chapter Four and Seven) that it correlates poorly with language capacity. Within certain IO ranges there is virtually no correlation whatever; and in the extreme low range, where there is an apparent correlation, it is rare to find individuals who have not even the capacity to understand simple spoken language. Most idiots and even imbeciles may be given verbal commands and many also acquire, spontaneously, the use of some words or even simple phrases. When the concept of intelligence must be applied to disparate species, the problem of scaling and measurement is enhanced greatly.


Clearly, intelligence is not a physical property that can be measured objectively. It is always tied to specific tasks and to the frame of reference of a given species. When we test different species by requiring animals to solve a certain problem, the similarity in task is seen by requiring animals to solve a certain problem, the similarity in task is seen by us, the human experimenter, but different species are likely to “interpret” an apparently similar task in their own, species-specific manner. Comparing the intelligence of different species is comparable to making relative measurements in different universes and comparable the results in absolute terms. When we say that a cat is more intelligent than a mouse, and a dog more intelligent than a cat, we do not mean that the one can catch the other by superior cunning but that one solves human tasks with greater ability than the other. The animal’s way of “interpreting” a problem situation becomes more and more similar to that of humans as the experimental animal is phylogenetically closer to man. But from this we cannot infer that language acquisition is just another problem-solving experiment and that phylogenetic proximity to man increases the capacity for language.


No comments: