A comparison of language in retarded children with language development of normal children indicates that there is a “natural language-learning strategy” that cannot be altered by training programs. Language unfolds lawfully and in regular stages. Language progress in the retarded appears to be primarily controlled by their biological maturation and their development of organizational principles rather than intelligent insight. The pathologically lowered IQ of the retarded does not result in bizarre use of language but merely in “frozen” but normal primitive language stages.
A remarkable degree of language competence is achieved by the congenitally deaf, despite apparently overwhelming handicaps. Thus, language may still develop under very abnormal conditions. The specific teaching of grammatical rules (no matter whether they are old-fashioned ones or modern) does not appear to help the children substantially in their language development. There is no reason to doubt that their language proficiency would develop in the same manner as it develops in the hearing who are simply given a great number of grammatical (and often semigrammatical) sentences from which they abstract the structural principles by which they themselves begin then to form new sentences. Deaf children could hardly differ in the capacity for doing this from hearing children, provided they were given enough examples and are allowed to go through a natural order of grammatical development. We do not know how hearing children develop their ability to abstract structural principles, and we do not know how deaf children might do it. But this is no reason to try to instill language habits by means (teaching of grammatical rules) which have never been shown to be of any use for any other language-learning child.
Language and cognition
I. THE PROBLEM
The general problem to be considered in this chapter may be called the problem of reference; that is, the relationship between words and things, and the role that our capacity for naming may play in man’s organization of cognition.
That the capacity for naming has a biological dimension may be seen from the difficulties that animals experience in this respect. For instance, it is possible to train a hunting dog to “point,” and it may be quite possible to teach him to point to a specific set of objects in a specific environment upon appropriate command in a natural language. But it does not appear to be possible to teach a dog to do the “name-specific stimulus generalization” that every child does automatically. The hound who has learned to “point to the tree, the gate, the house” in the trainer’s yard will perform quite erratically when given the same command with respect to similar but physically different object in an unfamiliar environment. The correctness of the animal’s responses may even vary with such extralinguistic cues as the geographical position, posture, and bodily movements of his master, the time of day, or the clothes that people are wearing while he is being exercised. There is no convincing evidence that any animal below man has ever learned to that word in common language-usage. So-called proof to the contrary always lacks proper controls on interpretation. For instance, there is a report on a parrot who could say good-by (in German) and who supposedly knew what this word meant or when it is properly used. Once the bird was also heard to say good-by upon the arrival of some friends of the family; the proud owner judged this to be a sign that his pet did not merely know the meaning of the word but was even using it to produce a desired effect: to send the just-arrived friends away, presumably because he had taken a dislike to them.
It may be well to stress once more that our concern is with the capacity for (natural, human) language which, ordinarily, leads to the understanding of a definably structured type of utterance; or, in other words, with knowing a language. The infant who has a repertoire of three tricks (wave by-by, show me your tongue, show me how tall you are) which he can perform upon the appropriate commands but who can understand no other sentence of the same grammatical, structural type has not yet begun to acquire language. The essence of language is its productivity; in the realm of perception and understanding of sentences, it is the capacity to recognize structural similarities between familiar and entirely novel word patterns. Thus our criterion for knowing language is not dependent upon demonstrations that an individual can talk or that he goes through some stereotyped performance upon hearing certain words, but upon evidence that he can analyze novel utterances through the application of structural principles. It is the purpose of this chapter to show that the understanding of the word-object relationship, the learning and acquisition of reference, is also dependent upon certain cognitive, analytic skills, much the way understanding sentence is. The problem of reference cannot be discussed without simultaneous considerations of the relationship between language and cognition.
Evidence for understanding language may be supplied by different kinds of response. It is not necessary that the subject has the anatomical and physiological prerequisites for actual speech production. In the case of man, we may cite children who have learned to understand language but who cannot speak; compare this to children who have the anatomical equipment for speech production but whose cognitive apparatus is so poorly developed that only the primordial for language are detectable but not fullfledged comprehension. In the case of animals, we have birds who can talk but who give no evidence of language understanding and we have famous case of Clever Hans, the horse, who had a nonacoustic response repertoire (stamping of hoofs) that, unfortunately, gave the erroneous impression of a coding system for the German language. Had the horse actually had the cognitive capacity for acquiring a natural language, his motor response limitations would have been no obstacle to his giving evidence for language comprehension. A similar argument could be made for the physical nature of the input data. Language acquisition is not dependent in man upon processing of acoustic patterns. There are many instances today of Deaf-and blind people who have built up language capacities on tactually perceived stimulus configuration.