This section is from "Scientific American Supplement Volumes 275, 286, 288, 299, 303, 312, 315, 324, 344 and 358". Also available from Amazon: Scientific American Reference Book.
A chapter is devoted to imitative movements. At the end of the fifteenth week the child would imitate the movement of protruding the lips, at nine months would cry on hearing other children do so, and at twelve months used to perform in its sleep imitative movements which had made a strong impression while awake--e.g., blowing; this shows that dreaming occurs at least as early as the first year. After the first year imitative movements are more readily learned than before.
Shaking the head as a sign of negation was found by Preyer, as by other observers, to be instinctive, and he adopts Darwin's explanation of the fact--viz., that the satisfied suckling in refusing the breast must needs move its head from side to side. In the seventeenth month the child exhibited a definite act of intelligent adjustment, for, desiring to reach a toy down from a press, it drew a traveling-bag from another part of the room to stand upon. We mention this incident because it exhibits the same level of mental development as that of Cuvier's orang, which, on desiring to reach an object off a high shelf, drew a chair below the shelf to stand upon. Anger was expressed in the tenth month, shame and pride in the nineteenth.
Between the tenth and eleventh month the first perception of causality was observed. Thus on the three hundred and nineteenth day the child was beating on a plate with a spoon and accidentally found that the sound was damped by placing the other hand upon the plate; it then changed its hands and repeated the experiment. Similarly at eleven months it struck a spoon upon a newspaper, and changed hands to see if this would modify the sound. In some children, however, the perception of causality to this extent occurs earlier. The present writer has seen a boy when exactly eight months old deriving much pleasure from striking the keys of a piano, and clearly showing that he understood the action of striking the keys to be the antecedent required for the production of the sound.
The third part of the book is concerned, as already stated, with the development of the understanding. Here it is noticed that memory and recognition of the mother's voice occurs as early as the second month; at four months the child cried for his absent nurse; and at eighteen months he knew if one of ten toy animals were removed. In Preyer's opinion--and we think there can be no question of its accuracy--the intelligence of a child before it can speak a word is in advance of that of the most intelligent animal. He gives numerous examples to prove that a high level of reason is attained by infants shortly before they begin to speak, and therefore that the doctrine which ascribes all thought to language is erroneous.
Highly elaborate observations were made on the development of speech, the date at which every new articulate sound was made being recorded. The following appear to us the results under this head which are most worth quoting.
Instinctive articulation without meaning may occur as early as the seventh week, but usually not till the end of the first half year. Tones are understood before words, and vowel sounds before consonants, so that if the vowel sounds alone are given of a word which the child understands (thirteen months), it will understand as well as if the word were fully spoken. Many children before they are six months old will repeat words parrot-like by mere imitation, without attaching to them any meaning. But this "echo-speaking" never takes place before the first understanding of certain other words is shown--never, e.g., earlier than the fourth month. Again, all children which hear but do not yet speak, thus repeat many words without understanding them, and conversely, understand many words without being able to repeat them. Such facts lead Professor Preyer to suggest a somewhat elaborate schema of the mechanism of speech, both on its physiological and psychological aspects; but this schema we have not sufficient space to reproduce.
Although the formation of ideas is not at first, or even for a considerable time, dependent on speech (any more than it is in the case of the lower animals), it constitutes the condition to the learning of speech, and afterward speech reacts upon the development of ideation. A child may and usually does imitate the sounds of animals as names of the animals which make them long before it can speak one word, and, so far as Preyer's evidence goes, interjections are all originally imitative of sounds. Children with a still very small vocabulary use words metaphorically, as "tooth-heaven" to signify the upper gums, and it is a mistake to suppose that the first words in a child's vocabulary are invariably noun-substantives, as distinguished from adjectives or even verbs. As this statement is at variance with almost universal opinion, we think it is desirable to furnish the following corroboration. The present writer has notes of a child which possessed a vocabulary of only a dozen words or so. The only properly English words were "poor," "dirty," and "cook," and of these the two adjectives, no less than the noun-substantive, were always appropriately used. The remaining words were nursery words, and of these "ta-ta" was used as a verb meaning to go, to go out, to go away, etc., inclusive of all possible moods and tenses. Thus, for instance, on one occasion, when the child was wheeling about her doll in her own perambulator, the writer stole away the doll without her perceiving the theft. When she thought that the doll had had a sufficiently long ride, she walked round the perambulator to take it out. Not finding the doll where she had left it she was greatly perplexed, and then began to say many times "poor Na-na, poor Na-na," "Na-na ta-ta, Na-na ta-ta;" this clearly meant--poor Na-na has disappeared. And many other examples might be given of this child similarly using her small stock of adjectives and verbs correctly.
According to Preyer, from the first week to the fifth month the only vowel sounds used are ü and a. On the forty-third day he heard the first consonant, which was m, and also the vowel o. Next day the child said ta hu, on the forty-sixth day gö örö, and on the fifty-first arra All the vowel sounds were acquired in the fifth month. We have no space to go further into the successive dates at which the remaining consonants were acquired. In the eleventh month the child first learnt to articulate a certain word (ada) by imitation, and afterward repeated the taught word spontaneously. The first year passed without any other indication of a connection between articulation and ideation than was supplied by the child using a string of different syllables (and not merely a repetition of the same one) on perceiving a rapid movement, as any one hurriedly leaving the room, etc.; but this child nevertheless understood certain words (such as "handchen geben") when only fifty-two weeks old. Inefficient attempts at imitative speaking precede the accurate attempts, and at fourteen months this inefficiency was still very apparent, being in marked contrast with the precision whereby it would imitate syllables which it could already say; the will to imitate all syllables was present, though not the ability. At the beginning of the fourteenth month on being asked: "Wo ist dein Schrank?" the child would turn its head in the direction of the cupboard, draw the person who asked the question toward it (though the child could not then walk); and so with other objects the names of which it knew. During the next month the child would point to the object when the question was asked, and also cough, blow, or stamp on being told to do so. In the seventeenth month there was a considerable advance in the use of sign-language (such as bringing a hat to the nurse as a request to go out), but still no words were spoken save ma-ma, pa-pa, etc. In the twentieth month the child could first repeat words of two unlike syllables. When twenty-three months old the first evidence of judgment was given; the child having drunk milk which was too hot for it, said the word "heiss." In the sixty-third week this word had been learnt in imitative speaking, so it required eight and a half months for it to be properly used as a predicate. At the same age on being asked, "Where is your beard?" the child would place its hand on its chin and move its thumb and fingers as if drawing hair through them, or as it was in the habit of doing if it touched its father's beard; this is evidence of imagination, which, however, certainly occurs much earlier in life. At the close of the second year a great advance was made in using two words together as a sentence--e.g., "home, milk," to signify a desire to go home and have some milk. In the first month of the third year sentences of three or even four words were used, as "papa, pear, plate, please." Hitherto the same word would often be employed to express several or many associated meanings, and no words appeared to have been entirely invented. The powers of association and inference were well developed. For instance, the child received many presents on its birthday, and being pleased said "bursta" (=Geburtstage); afterward when similarly pleased it would say the same word. Again, when it injured its hand it was told to blow upon it, and on afterward knocking its head it blew into the air. At this age also the power of making propositions advanced considerably, as was shown, for instance, by the following sentence on seeing milk spilt upon the floor: "Mime atta teppa papa oï," which was equivalent to "Milch fort (auf den) Teppich, Papa (sagte) pfui!" But it is interesting that at this age words were learnt with an erroneous apprehension of their meaning; this was particularly the case with pronouns--"dein Bett," for example, being supposed to mean "das grosse Bett." All words which were spontaneously acquired seemed to be instances of onomatopoeia. Adverbs were first used in the twenty-seventh month, and now also words which had previously been used to express a variety of associated or generic meanings, were discarded for more specific ones. In the twenty-eighth month prepositions were first used, and questions were first asked. In the twenty-ninth month the chief advance was in naming self with a pronoun, as in "give me bread;" but the word "I" was not yet spoken. When asked: "Wer ist mir?" the child would say its own name. Although the child had long been able to say its numerals, it was only in this month that it attained to an understanding of their use in counting. In the thirty-second month the word "I" was acquired, but still the child seemed to prefer speaking of itself in the third person.