Hadow (1931)

Notes on the text
Preliminary pages Membership, Analysis, Preface, Introduction
Chapter 1 The history of the development of the conception of primary education
Chapter 2 The physical development of children between the ages of 7 and 11
Chapter 3 The mental development of children between the ages of 7 and 11
Chapter 4 The age limits for the upper stage of primary education
Chapter 5 The internal organisation of primary schools
Chapter 6 Retarded children in the primary school
Chapter 7 The curriculum of the primary school
Chapter 8 The staffing of primary schools and the training of teachers
Chapter 9 The premises and equipment of primary schools
Chapter 10 Examinations in primary schools
Chapter 11 Summary of principal conclusions and recommendations
Chapter 12 Suggestions on the curriculum of primary schools
Appendix I List of witnesses
Appendix II Physical development of 7-11 year olds (Harris)
Appendix III Mental development of 7-11 year olds (Burt)
Index

London: HM Stationery Office

Chapter 2 The physical development of children between the ages of 7 and 11
[pages 22 - 32]

25. There is a large body of traditional and conventional views regarding the physical and mental development of young children up to the age of eleven. Such opinions represent the cumulative experience and observations of successive generations of parents, teachers, inspectors and administrators. Of late years, however, the accuracy of many of these time-honoured notions about children has been called in question by scientific investigators - both physiologists and psychologists. Much attention has been devoted to the systematic study of children at the infant stage and also at the adolescent period, but the intermediate stage between the ages of seven and eleven, up to the present, has been comparatively neglected. It therefore seems to us most important for the purpose of our present inquiry to summarise such knowledge as is available regarding the anatomy and physiology of growth and the general mental development of children at this period.

The teacher, in particular, will appreciate the significance of the inferences that may legitimately be drawn from the brief summary of the basic facts of physical and mental development which is attempted in this and the following chapter. It is true, no doubt, that the extent to which he may modify his methods of teaching and treatment to meet the needs of the individual child will vary. But the necessity of recognising adequately the general characteristics of school children during this middle period of their growth, will justify a close study by the teacher of such physiological and psychological evidence as is available.

26. A comparison of the growth curve for man with that for domesticated animals indicates that among the most precious heritages of man are his long period of gestation and his slow development through a prolonged childhood. In the domestic animals there is only one 'springing-up' period after birth, and the age of the suckling is rapidly followed by the age of the second dentition and of puberty. There is in their development nothing corresponding to the 'first' and 'second filling-out' periods in the growth of the human child, described in section 27. For instance the pup doubles his weight in the first week of life, cuts his milk teeth in the first month, the second teeth in the fourth month, and is sexually mature at the age of one year. The child grows most slowly of all the animals, continues to evolve for a long period of time, and has greatly spaced out these stages in the development which in other animals follow far more rapidly.

Our medical witnesses explained that there were at least four clearly defined types of aspects of growth in the human organism, the skeletal, the neural, the lymphoid, and the genital.

The skeletal type of development described briefly in section 27, which may be represented graphically as a growth curve, relates only to modifications in height and weight, and cannot be regarded as an adequate representation of the profound changes that take place at successive stages in the development of any given child. Almost every external linear dimension of the body, excepting the head and neck, falls under this type of growth. The skeleton as a whole, the length of the limbs, the development of the thoracic cage, of the respiratory apparatus and of the muscular system, present this general type of skeletal growth.

The neural type. The brain, the spinal cord, the eyeball and the skull display a peculiar type of growth which may be described as neural. During the first eighteen months of post-natal life these organs develop with great rapidity. When the infant has reached the age of two, his brain has attained 60 per cent of its adult size, and by the age of seven it has almost reached adult size.

The lymphoid type. The lymphoid tissue of the body, as illustrated by the lymphatic glands, tonsils and thymus, develops rapidly in childhood and continues to grow at a somewhat slower rate up to puberty. During adolescence and adult life there is both an absolute and a relative decrease in the amount of lymphoid tissue. Professor Harris pointed out that this type of growth must be of profound significance in the development of young children, in view of the extent to which the lymphoid glands in children were involved at all stages of their development whether as a result of acute disease or of chronic infections.

The genital type. A fourth type of growth is that presented by the genital organs. These organs grow but slowly in infancy, are almost stationary from the age of two to that of ten, and develop rapidly in the two years before puberty, during puberty, and at adolescence.

Our medical witnesses, however, stressed the fact that these four types of growth are at best only crude representations of the complexity of the processes actually involved.

27. The salient facts in regard to the successive stages of growth in young children may be briefly stated as follows:

The infant in the month before birth develops more rapidly than at any other period. During the first year of post-natal life it grows rapidly, and this stage may be described as the 'first springing-up' period. Between the ages of one and five years, the infant grows more slowly and more steadily. This stage may be called the 'first filling-out' period. From the age of five to that of seven, there is a 'second springing-up' period. At this stage, the child increases rapidly in height, loses its milk teeth, and begins to cut its second or permanent teeth; it becomes thin and long in the limbs, and exchanges the chubbiness of babyhood for the characteristic family type of face. At the age of seven the child's head is almost as large as it will ever be. The cutting of the second teeth is frequently accompanied by nervous disturbances, as significant in their way as those associated with the first dentition. Other features of this period are the marked development of the air sinuses in the face and nose, the rapid lengthening of the feet in the sixth year, and the tendency of many children to 'go thin' on account of the loss of subcutaneous fat.

From the age of seven to that of eleven or twelve, there is a second 'filling-out' period, with its characteristic of steady growth. This is followed by the 'third springing-up' period associated with puberty. The striking changes associated with the rapid growth of the organism during puberty gradually gives place to the 'third' and last 'filling-out' period, as puberty passes into adolescence.

It will thus be seen that each of the three 'springing-up' periods is in turn followed by a 'filling-out' period; each stage has its special characteristics. The normal development of all these stages is liable to be disturbed by oscillations of growth, and may be modified by diet, environmental conditions and disease. It should be mentioned that the human growth curve has been recently described by several physiologists as showing only two outstanding periods of accelerated growth, that immediately before and after birth and that of adolescence. These two stages of rapid development are superimposed upon a process of steady growth out of which the accelerations arise. This process of regular and steady growth leads in healthy children to an annual increase in weight of about 4.5 Ibs (2 kilograms) between the ages of two and twelve. In this short statement, however, the older conception of three 'springing-up' periods has been retained on clinical grounds which, for the present, appear to be more trustworthy. The graphical representation of the 'second springing-up' period between the ages of five and seven is to a great extent obscured in many curves of increase in height and weight based on mass statistics, but when children are examined as individuals the changes in body build at the time of the onset of the second dentition are noticeable and significant. The rapid increase in height and foot length, the changes in the proportions of the limbs and the peculiar susceptibility to certain diseases, justify the retention of the older conception of three 'springing-up' periods. It cannot be too strongly emphasised that curves of height and weight give but an imperfect picture of the marvellously complex mosaic of patterns of growth involved in the different systems of the human body. At any one particular moment in the child's life one or more organs may exhibit a rapidity of growth which may or may not be reflected in the development of other organs. Furthermore, the ages selected in discussing the six cycles of growth should be regarded as crude landmarks only and not as strict lines if biological demarcation. The differences in the ages of onset of puberty and menstruation in particular indicate a wide variation in terms of race, social status, environment, nutrition, and family stock.

28. The evidence indicates that in general the three 'springing-up' periods are peculiarly associated with certain diseases, and that illness occurring at any year of school age tends to leave more severe sequelae [diseases occurring as a result of previous illness], if it comes within one of the 'springing-up' periods, when the child's organism is already taxed to the utmost in providing the energy necessary for growth. During the first 'springing-up' period to the end of the first year of post-natal life, the infant is specially prone to certain nutritional diseases, such as infantile diarrhoea, rickets, scurvy, and digestive disturbances. During the first 'filling-out' stage between the ages of one and five, and to a greater extent during the second 'springing-up' between the ages of five and seven, the incidence of acute infections and fevers, such as measles, whooping cough, chicken pox, scarletina and diphtheria is heavier than at other periods.

Some of these epidemic diseases tend to leave serious after effects. For instance whooping cough and measles, which involve the respiratory tract, may be followed by tuberculosis in the glands of the chest, and scarlet fever in children between the ages of five and seven is not infrequently followed by running ears and nephritis. Further, the milk teeth of many children, instead of being replaced by the normal process of aseptic absorption, often become infected and suppurate before they disappear, and are apt to cause digestive troubles.

During the second 'filling-out' period between the ages of seven and eleven the incidence of acute infectious diseases is less heavy, but the chronic sequelae of preceding infections may be observed in many children, specially in the lymphoid system of the neck, chest and abdomen. Thus the problems presented by this stage of development largely centre in the heritage of the diseases and deficiencies of the preceding years. In particular, the second teeth, defects in visions, enlarged tonsils and adenoids, disease of the middle-ear, and disease of the lymphatic glands in the chest, neck and abdomen, demand careful attention. In fact, this period of consolidation between the ages of seven and eleven may justly be regarded as affording the best opportunity for retrieving past defects in development, and preparing the organism to meet the heavy demands entailed by rapid growth during the third 'springing-up' period of puberty, when the child is apt to outgrow his strength, and again becomes more liable to infectious diseases.

Our medical witnesses were disposed to think that hygienic grounds confirmed the general practice of transferring children from the infant to the primary school at about the age of seven.

29. In the new-born child the actual muscle accounts for less than 25 per cent of the body weight. In the young adult the muscle accounts for about 43 per cent; the muscular system which is closely linked up with the skeletal system in respect of its type of growth develops most rapidly during the last two months of antenatal life, and again during the latter part of puberty and adolescence. At all age periods it wastes very quickly in acute illness and starvation, and responds to feeding and exercise. During the periods of rapid growth it is a particularly sensitive recorder of harmful stimuli, which are apt to affect the fast-growing tissues.

The two bones forming the shoulder blade are not united until puberty. The three bones which unite to form the hip bone do not coalesce till about the age of fifteen in girls and sixteen in boys. The formation of these two sets of composite bones, the shoulder blade and the hip bone, is of fundamental significance, and indicates quite clearly the age at which it is safe to subject a given individual to heavy muscular work. Our medical witnesses urged strongly that no boy or girl up to these ages should be subjected to intense or sustained muscular effort. These anatomical landmarks on the growing child are definite and precise, and cannot be disregarded without peril.

The erect attitude in itself remains a severe muscular feat since it involves the transference of the weight formerly shared equally between four limbs in the quadruped to two limbs in man. This attitude is very fatiguing and is in fact a highly unstable position, both on account of the small size of the base covered by the feet, and the high position of the centre of gravity. It was pointed out that children must not be expected to stand like soldiers at attention. The natural attitude for a child is that which he adopts when playing. He stands with feet apart and knees bent, and delights in squatting. In view of these considerations we agree with the views expressed by many of our witnesses that adequate facilities for rest should be provided for young children, especially after the midday meal.

30. Recent research has shown that every severe illness, whether due to acute infection or to disease of the respiratory system, such as bronchopneumonia, dislocates the normal metabolism and growth of the child, and that such illnesses are recorded on the bones as lines of arrested growth. When the child is ill, or starved, the epiphysial growth cartilage at the end of the shaft of the long bones ceases to proliferate, and becomes heavily calcified. (1) When growth is resumed after the removal of the harmful conditions, this line of arrested development appears as a scar on the bone. In the same way any disturbance of the metabolism of the body caused by disease or severe emotional shock is frequently indicated by a ridge across the finger nails. Though little is known as yet of the extent to which illness affects the growth and development of those organs which exhibit the neural, lymphoid and genital types of growth, the extent to which the skeletal system is involved is far greater than anyone has suggested in the past. Particular attention was called to the danger of urging young children to work hard before they had completely recovered from illnesses.

31. Variations in general body build and in the form, size and position of the internal organs of digestion indicate that there is a real correlation between the skeleton and these organs. Our physiological witnesses informed us that several attempts had been made to classify the varying types of body build on this basis. For instance, a child of stout stocky build requires a digestive system of great motility [capable of motion] and rapid contractions to accommodate and assimilate the comparatively large amount of food commensurate with its activity. Mills distinguishes four main types, namely, hypersthenic, sthenic, hyposthenic and asthenic. In children of the hypersthenic type, the radiographs show that the viscera are in a high position. In weakly children of the asthenic type, the viscera are low in position, and the motility and powers of muscular contraction of the gut are small. Our medical witnesses pointed out that a child by reason of illness or starvation does not undergo any considerable changes of body build and cannot be converted from the hypersthenic type to the asthenic type. The four main types of Mills, however, admit of a further classification in terms of sub-types, and our medical witnesses thought that by appropriate feeding and exercise a given child might advance from one sub-type to a neighbouring one. There is thus a definite limit to the amount of change in physique that can be impressed upon a growing child. The existence of these different types of human organism, each consistent with good health and efficiency, (2) each with its peculiar characteristics in respect of the amount of food required, each with a tendency to react acutely to certain diseases, or even to be predisposed to them, appears to be a fundamental fact of biology. This consideration always tends to impair the significance of mass statistics, and to invalidate the results of large scale experiments. The school medical officer, realising the significance of the body build of each individual child, and the susceptibility to disease involved therein, can do much to guarantee to each child that measure of growth and physical efficiency which is the norm for his particular type.

32. The brain is the part of the nervous system most closely associated with mental life, and its growth might, therefore, be expected to throw special light upon the development of the child's mind. Our physiological and psychological witnesses, however, informed us that very little is known with any certainty about the development of the brain, though various ingenious attempts have been made to correlate brain weight at successive stages of growth with body weight and to explain the significance of the development of the surface area of the human brain. Up to the age of about six or seven, the brain increases rapidly in size and weight, but after that age it grows comparatively little, though the body as a whole at the age of seven is only one third of its adult weight. An almost imperceptible enlargement continues year by year until the age of twelve or fourteen, when it attains what may be regarded as virtually its maximal size. Thus in size and weight the brain grows more and more slowly from the age of seven onwards. The index of cerebral value recently drawn up with great care by Anthony and Coupin, which claims to present a definite picture of the 'urge' of brain growth, indicates that the sixth and seventh year of a child's life, which correspond to the second 'springing-up' period of skeletal growth described in section 27 above, appear to be very important years in respect of brain growth.

The architecture of the brain in the child from seven to eleven still awaits intensive study and we are acquainted only with the gross differences between the new-born and the adult. Certain facts which have emerged from the comparison of the foetus, the new-born babe, and the adult, have an important bearing on the problems of education. In any given area of the cortex of the brain, the single layer of nerve cells in the foetus of four months undergoes differentiation into three layers of cells. These layers are called from within outwards the polymorphic, or inner cell lamina, the granular or middle cell lamina, and the pyramidal or outer cell lamina. The three laminae are distinct at birth, and it is the outer cell lamina, the last to appear, which grows most noticeably during childhood. In any form of amentia (3) it is the outer cell lamina which fails to develop and the middle cell lamina to a slighter extent. Further, in any form of dementia (4) this outer cell lamina, which is the last to develop, is the first to undergo dissolution.

The fact that the order of appearance in normal growth is known, that the susceptibility of the various laminae to maldevelopment and decay is known, that the last layer to develop is the first to suffer, combined with the fact that this layer increases in thickness in the normal child from birth to maturity by more than fifty per cent, indicates the need for detailed knowledge of these processes in children of school age. It is possible that the processes of development and differentiation of the laminae of the cortex are susceptible to malnutrition and disease to a far greater extent than may at present be hazarded.

This process of differentiation of the cerebral cortex into three layers does not take place at the same time in all regions of the brain. It takes place in the visual cortex later than in the motor cortex, but before it occurs in the frontal cortex. In fact, that portion of the brain which is regarded as peculiarly associated with the higher functions is characterised by a later appearance of differentiation. The child kicks in the womb, sees when he is born, thinks later. Since the area of the brain concerned with thinking is the last to undergo differentiation, this area is brought more and more clearly into the age period when malnutrition and acute disease are most liable to register their effects.

It is highly important that the age changes in the cerebral cortex from birth to seven years should be studied more intensively. It is almost true to state that between the ages of two and eighteen years the changes are unknown. Excluding the gross changes found in aments and dements, it must be noted that, as there are wide individual variations in the degree of apparently normal cortical development, so there are wide variations in the degree of mental development in apparently normal infants and young children. (5) At present we do not know to what degree, if at all, these normal anatomical and mental variations are related, and further research is needed. In particular we want to know whether anatomical age changes are connected with the acquisition of new mental processes, and if so, to what extent; and how far mental processes once lost or impaired can be resumed.

33. The skeletal development varies noticeably in the sexes, the development of the bones in the girl being more rapid than in the boy. The centres of ossification of the bones in the girl appear days earlier in prenatal life, weeks earlier in babyhood, and from one to two years earlier in childhood and puberty. Furthermore, the epiphysical union and that knitting of the bones which indicates cessation of growth at the close of adolescence, occurs earlier in the girl. We were told that these variations in development between the sexes had a bearing on the problem of coeducation, since those sex differences which were frequently regarded as emerging at puberty were really more profound and were in operation from the early stages of embryonic life. The conventional view of the period between the ages of seven and eleven as a neutral stage was thus incorrect. The latest researches indicated that the boy was in fact a boy and a girl essentially feminine from the earliest period of embryonic life. Throughout childhood the growth of the skeletal and nervous systems, and of the ductless or endocrine glands (6), in the two sexes was distinct.

The psychological evidence which is summarised in Chapter 3 indicates that the mental differences between the sexes may be insignificant up to the age of eleven. It is evident, however, that the differences in physical development are very noticeable. We accordingly consider that it is desirable to warn teachers against assuming that, because boys and girls in 'mixed' schools can for the most part learn similar subjects at a similar pace during this age period, they therefore have identical capacity for muscular effort and like resistance to physical fatigue. We consider it important that even at this early stage appropriate physical exercises and appropriate games should be provided for the girls. The provision of facilities for rest to which we have already alluded, are particularly desirable for girls in view of their greater liability to fatigue.

Footnotes

(1) During the period of growth the long bones consist of a shaft (diaphysis) and two articular extremities (epiphyses) attached to the shaft by narrow plates of actively growing cartilage (epiphysial cartilages). When growth ceases, the epiphysial cartilages calcify and ossify, thus firmly binding the two epiphyses or ends to the diaphysis or shaft to form an adult bone.

(2) It was pointed out that such classifications of body build do not afford adequate grounds for predicting what the physical or mental qualities of any given child might be. Health and efficiency combined with unusual mental powers were often found in a body of poor physique. The available data indicated that a child of any given body build might well reach the maximum standard for his own particular type.

(3) Amentia is a condition in which the mind has failed to attain normal development, e.g. idiocy, imbecility, feeble-mindedness.

(4) Dementia is a condition in which the mind, having attained development, is undergoing degeneration and decay, e.g., senility, severe epilepsy.

(5) See Chapter 3, section 35.

(6) The ductless or endocrine glands do not discharge their secretion to the exterior, but give up their secretion directly to the blood or tissue-juice. Such glands are the thyroid, parathyroid, suprarenals, pituitary and pineal.

The lymphatic glands are masses of defensive tissue along the lymphatic vessels which return tissue-juice as lymph to the blood stream. These glands, of which the tonsil is a type, trap foreign bodies such as bacteria and are the seat of formation of some of the white blood corpuscles.