Mental development and education

Preface

In writing this volume the author has had constantly in mind the interests and needs of teachers in service and also persons who are preparing to teach. Consequently those aspects only of mental development and of education which directly concern •those who train the young have received attention ; all strictly technical and speculative discussion has been avoided. No attempt has been made to treat comprehensively the psychology of childhood and youth or educational values and methods. Two questions have guided the discussion throughout ; — first, How does the individual normally respond at different periods in his development to the typical situations, physical, intellectual, aesthetic and social, in which he is placed; and second, How can he best appropriate the materials and benefits of education so that he can utilize them to greatest advantage in daily Hf e ?

The point of view is that afforded by present-day biological psychology. For those who may not at first glance see just what this point of view is, it may be said that one who regards human nature from the standpoint of biological psychology seeks to explain the behavior of a child or a youth on the basis of natural laws governing the development of his body, his intellect and his character. It is seen that the individual is at birth equipped with tendencies which represent some of the activities which have proved of service in the life of his ancestors, and these tendencies are manifested in varying degrees and forms in the course of development from birth to maturity. But the child is born into an environment which is fundamentally different in many respects from that in which the impulses which he brings with him were vi PREFACE

established, and so he encounters difficulties in adjusting himself to the world in which he must live. It is the object of education in the school and in the home to assist the individual to make necessary modifications of and adjustments to his environments as easily and effectively and with as little strain and stress as possible. To secure information bearing on these matters, the writer has made observations and investigations on his own part and has studied the investigations made and views presented by others ; and he has endeavored to organize and interpret all available data, and present conclusions in straightforward, intelligible language.

Stress is laid in this volume on dynamic methods in teaching, and an attempt is made to observe the principles advocated by assigning an important place to exercises requiring the student to analyze and investigate problems, to interpret data bearing on various aspects of development and education, and to apply conclusions to original situations. It is the author's experience that most readers and students need the stimulus of concrete problems in order actually to master what they read or study, and especially to gain ability and facility in making practical use of the principles they acquire. So in Part III of this volume many photographs, diagrams, tables, graphs, quotations and queries are employed, all relating in an orderly way to subjects which are discussed in the text, and the reader is encouraged to utiHze all his resources in knowledge and critical method to throw light into dark places and to bring apparently divergent phenomena under a few basic principles of development and of education. A sufficient variety of exercises has been provided so that a class, a study circle, or an individual reader can select according to special interests, facihties for investigation, or degree of acquaintanceship with psychology and related sciences.

In 1905 the writer published a volume entitled "Dynamic Factors in Education," which was more or less of a pioneer in the

PREFACE vii

field which it covered. This book met with a generous welcome from teachers, and it has apparently played a small part at least in promoting dynamic methods of teaching in the schools of our country ; but the plates have become worn, and it has been decided not to reprint it. Consequently, it has seemed advisable to include in this volume a few of the more useful chapters, thoroughly revised, of the earlier book. It is possible that a reader of this volume may recognize some paragraphs which he saw in the earlier book, but the little that has been preserved from "Dynamic Factors in Education" has been brought into accord with the large amount of research that has been conducted in this field since the earlier book was written.

M. V. O'Shea

Part I Dynamic Aspects Of Mental Development

CHAPTER PAGE

I. Motive Forces in Development: Physical Well-being 3 A simple illustration of the nature and role of driving forces. Physical welfare. Predominance of the food-securing impulse. Self -protective impulses. Conflict of motive forces. Resistance to remedial treatment. The impulse to seek protection from wind and weather. Interest in clothing for decoration rather than for protection. Fear as a protective agent. Fear as a motive force in development.

II. Motive Forces in Development: Social, Intellectual

AND Esthetic Well-being 18

The passion for experiences with persons. The passion to communicate. The strongest force of all, — the wish to secure the good-will of one's fellows. Rivalry as a motive force. Resentment and aggression. Submission to leadership as a motive force. The urge to gain knowledge for its own sake. The constructive impulse as a motive force. The impulse to solve intellectual problems. The choice of the beautiful and avoidance of the ugly. Activities reminiscent of ancestral life. Environment vying with hereditary forces. Two forces acting on the child in his development.

III. Primtive Forms of Adaptive Activities: Trial and

Success; Imitation . . . . , . .35 The helplessness of the infant. The first step in acquiring adaptive activities. A concrete example of acquiring a

CONTENTS

AFTER PAGE

voluntary act. Learning involves excessive activity. The integration of simple acts into more complex adjustments. Nothing is learned de novo. Imitation as a form of adaptive activity. The phenomena of mimicry. When does imitation begin? Apperception in imitation. The principle illustrated in adult imitation. The course of development with respect to imitativeness.

I\'. Higher Forms of Adaptive Activity : Generalization ;

Symbolization ; Imagination ; Reason ... 54

The adaptive activities of animals. "King Pharaoh's" abilities. Types of intelligence. Sensori-motor response. A horse's responses depend upon visual, auditory or olfactory cues. The quahty of animal intelligence. Popular misconceptions regarding the abilities of animals. Illustrations of a dog's intelligence. One trait of distinctly human intelligence, — symbolization. Importance of symbolization in adaptive activity. Development of symbolizing activities in the chUd. The ability of the individual to develop free ideas. The ability to foresee consequences and adapt means to ends. Free concepts must be controlled by the ends to be attained. The most important distinction between the primitive and the higher types of intelligence. Analysis and synthesis.

\'. EXPRESSIONAL ACTIVITIES : VoCAL, FeATURAL, POSTURAL,

Gestural 77

Indefiniteness of the first efforts at expression. Ready-made means of expression. Darwin's view of the origin of expression. The expression of complex emotions. Organic accompaniments of emotion reenforce motor reactions. The James-Lange Theory. With the child expression is intense but of short duration. With the adult, expression is subdued, but it is more enduring than in the earlier years. Why does expression become subdued with development ? Women are more expressive than men. Racial differences in expression. The expression of thought. Reflection involves strain and effort. Purpose-

CONTENTS ful expressional activities. Gesture. Figurative gesture. The use of the gesture in conveying ideas of quality and of action. The use of gesture to emphasize feeling. Relation of gesture to language. Individual differences in the use of gesture.

VI. Expressional Activities: Graphic, Pictorial. . . ic6

The development of a sign language. The development of linguistic symbols. Scribbling activities. Studies of children's drawings. Difficulty of representation no barrier to expression. Older children are inhibited. The child's diagrams embody the most essential characteristics of objects. Always the same diagram for any given object. Special characteristics of objects not included in diagrams. Are logical relations revealed in children's drawings? Difficulty in representing special relations. Language acquired more easily and naturally than drawing. The psychology of drawing.

VII. The Development of Coordination 128

Coordination in infancy. The first stages in acquiring manual dexterity. The wave of development is toward the extremities. The development of pedal control. The development of coordination in speech. The principle illustrated in the child's use of sentences. The order of losing coordinations in degeneration.

VIII. The Development of Inhibition ; the Neurological and

Psychological View 140

Children's lack of inhibition. The effect of motor restraint on mental activity. Restraint comes with development. The neurological view of inhibition. Suggestions gained from the phenomena of degeneration.

IX. The Development of Inhibition; Restraining Forces . 154 The perfectly restrained individual. Experiences which develop restraint. Stages in acquiring restraint. Physical coercion not the only force that leads to rexii CONTENTS

CHAPTER PAGE

straint. Restraining influences operate differently at various stages in development. Imitation of self-restraint in others. The restraining influence of heroes in stories. The fusion of restraining forces. The weakening of an impulse. The role of formal education in developing restraint. The influence of ideals established in history, literature, et al. The restraining influence of habits established by study. Individual differences in the matter of self-restraint.

X. Activities Peculiar to Adolescence 169

Transformations occur abruptly during puberty. Boys form gangs. The boy is interested in tribal activities. The boy's tribal interests wiU flourish only in the gang. The larger the gang the more tribal its interests. The gang promotes pugnacity. Muscular contests. Stealing. The instinct of acquisition. Destruction of property. Profanity and the use of tobacco go hand in hand with steahng, etc. Truancy. Swimming. Competition in games. Girls form "sets" which are only loosely organized. Activities growing out of sex-interest. Eagerness to find a job.

Part II Educational Interpretations

XI, Dynamic Education: Content Studies . . . .187 The meaning of dynamic education. How the child is enabled to interpret the world about him. The dynamic principle illustrated in the Montessori schools. The dynamic principle applied in arithmetic. The dynamic principle applies to all studies. Dynamic methods in secondary education. Making rhetoric dynamic. The teaching of science in the high school. Dynamic teaching of citizenship. Developing patriotism. The first step in developing love of country. We are all members of one body. The study of community life.

CONTENTS xiii

CHAPTER PAGE

XII. Dynamic Education: The Role of Suggestion . . 205 Action follows the direction of attention. The constructive treatment of aches and ills. One can intensify children's misfortunes by suggestion. The use of suggestion in the sick room. One's defects may be increased by suggestion. The morals of a community may be elevated or degraded by suggestion. Suggestion in the theater.

XIII. Overstrain in Education: Wasteful Practices . .218

Present-day conditions that cause overstrain. The chief cause of overstrain. The need for periods of quiet. Wasting nervous energy in the home. The teased child. Noise as a nervous irritant. Overstrain in the schools. Waste from excessively fine work. Unnecessary tension in writing. Concerning pens. The typewriter is less wasteful than the pen. Postures that lead to waste of energy. The eye in relation to nervous waste. Maladjustment of ocular muscles. Maladjustment of the lens. Dr. Gould on the efifects of eye-strain. Importance of the teeth in relation to saving waste of vitality.

XIV. Overstrain in Education: Conditions Affecting

Endurance 263

Handicaps to endurance. Why people differ in power of endurance. Training for mental endurance. Training can be overdone. "Off days." The law of economy in developing and maintaining organs. Organs that are not used tend to degenerate. Intelligence is in the ascendancy. The price of "refined" training. Hardening the body. New social conditions make our problem a very complicated one. Overeating and under-cleaning. Health and cleanliness. Blue Monday. Energy in relation to indoor air. What are the requirements for good ventilation? The toxic efifect of "dead" air. The role played by clothing in maintaining vigor. Energy in relation to indoor temperature. Arranging a heating system so as to overcome inequality in temperature between head and floor levels.

xiv CONTENTS

Part III Exercises In Analysis, Interpretation, Investigation And Application

CHAPTER PACE

I. Motive Forces in Development: Physical Well-being 2qi

II. Motive Forces in Development: Social, Intellec tual and ^Esthetic Well-being ....

III. Primitive Modes of Adaptive Activity : Trial and

Success ; Imitation

IV. Higher Forms of Adaptive Activity: Conception

Symbolization ; Imagination; Reason .

V. ExPRESSiONAL ACTIVITIES: VocAL, Featural, Postural Gestural

VI. Expressional Activitles: Graphic, Pictorial .

VII. The Development of Coordination ....

VIII. The Development of Inhibition ; the Neurological and Psychological View

IX. The Development of Inhibition; Restraining Forces

X. Activities Peculiar to Adolescence ....

XI. Dynamic Education: General Principles

XII. Dynamic Education: The Role of Suggestion

XIII. Overstrain in Education: Wasteful Practices

XIV. Overstrain in Education: Conditions Affecting En

durance

Authors Referred -to or Quoted in the Text .

295 301 310

319 325 329

332 338 344 356 368 377

390 395 397

FIGURES IN THE TEXT

I. 4- 5- 6

7- 8.

lO.

II

i6

Children's Passion for Swimming and Playing Games in the Water

Children's Passion for Constructive Activities

The Nomadic Impulse during the Teens

Children's Interest in Dramatic Activities .

Children's Passion for Impersonation ....

The Animal Brain as Compared with That of Man .

Phrenological Chart

Chart Illustrating Chiromancy

Studies in the Expression of the Brow

Studies in the Expression of the Lips ....

Studies in the Expression of the Eyes ....

The Evolution of the Letter M

Examples of Pictorial Writing

Examples of Pictorial Writing

A Child's Drawing for "Jack and the Bean Stalk." A Child's Drawing for " Johnny-Look-in-the-Air"

Second Drawing for "Johnny-Look-in-the-Air"

Third Drawing for "Johnny-Look-in-the-Air" Fourth Drawing for "Johnny-Look-in-the-Air" Fifth Drawing for "Johnny-Look-in-thc-Air" Effect of Children's Efiforts to Perform Coordinated Tasks Activities Requiring Use of the Large IMuscles Principally Tasks That Do Not Require Fine Coordination . Tasks Requiring Varying Degrees of Coordination The Brains of (a) Normal Adult ; (b) Adult Idiot ; (c)

born Child

Scene in the Vicinity of a Public School in a Large City

Competitive Games for Girls

Indoor Games

Curve Showing Annual Increase in Endurance, Vital Capacity

Weight and Grip of Right Hand Scene in an American Dance Hall

New

14 25 29

31 46 no

no

131 132 134 138

141 144 147

XVI

FIGURES IN THE TEXT

Seat and

FIGURE

_28. Boys in the Early Adolescent Period . An Educational Object Lesson Learning Tables of Measurement by Actual Use Judging Different Varieties of Corn .

Fourteen Nationalities in One School .

Plethysmographic Record from the Arm of a Sleeping Person Record Showing Effect of Noise on a Sleeping Subject Different Styles of Penholders ....

A Posture Frequently Seen in Home and School Overdoing the Effort to Maintain Erect Posture Postures That Lead to Deformities Posture Induced by a Too High Seat .

Posture Induced by Relation of Seat to Desk Effect of Too Small Distance between Seat and Desk Posture Induced by Too Small Desk and Chair . Posture Induced by Too Great Distance between

Desk

Proper Adjustment of Desk and Chair

Posture Induced by Too High Desk .

Muscles of the Eyeball

The Normal Eye ....

The Shortsighted or Myopic Eye

The Longsighted or Hyperopic Eye .

The Double Concave Lens .

Concave Lens to Correct Myopia

The Double Convex Lens

Convex Lens to Correct Longsightedness

The Astigmatic Dial ....

Chart Showing Astigmatism

A Shortsighted Astigmatic Eye .

Another Type of Shortsighted Astigmatic Ey

The Longsighted Astigmatic Eye

An Astigmatic Eye in Which Rays Focus on the Retina in One

Meridian and behind the Retina in Another Meridian Astigmatic Eye in Which Rays Focus in Front of the Retina

One Meridian and behind the Retina in Another Meridian Postures Which Determine Mental States .... Seating Which Will Secure Erect Posture ....

247 254 255

FIGURES IN THE TEXT xvu

73- 74- 75- 76.

77- 78.

83. 84. 85.

Fairhui)o Method of Inducing Children to Relax School Facilities for Relaxation ...

Outdoor Calisthenics

Competitive Games Which Develop Endurance

The Chief Malady of the Schoolroom .

The Nomadic Impulse

The Throwing Impulse

Operating a Linotype Machine

Work for Backward Children

A Study in Expression

A Study in Expression

Children's Spontaneous Drawing:

Children's Spontaneous Drawings

Children's Spontaneous Drawings

Relative Proportions of Child and Adult

Relations of Adolescent Boys and Girls

Cultivating the Soil ....

The Meeting-Place of the Gang .

Dynamic Methods of Teaching Pyramids and Cones

Learning How to Take Care of a Baby

Learning How to Make a Bed

One Method of Lighting a Schoolroom

Curvature of the Spine

PAGE

Chapter I Motive Forces In Development: Physical Well- Being

A COMPLICATED subjcct may perhaps best be introduced by a. simple illustration. In the spring one plants a bean seed in moist earth. Soon the young plant will break through ^ ^^^^^ the soil. Roots will push downward into the earth, illustration and stalk, branches and leaves will appear above and rsie of the earth. If there is an obstruction in the path of drivingforces the roots, they will turn out of their course in order to avoid it. So above the soil, — if the space directly overhead is already occupied by another plant, the new one will bend this way or that so as to take advantage of any unoccupied space. Finally blossoms will appear and then the seeds will develop. When the seeds are matured the plant will disintegrate.

It is apparent that the ultimate purpose which governs the activities of the plant in its life career is the production of seed, and every detail of its development has reference to the attainment of this goal. It seeks to fasten itself in the earth so that it will not be torn up by the winds. It struggles to obtain moisture and constructive materials which are essential to the building of the supporting structures necessary to bear the leaves and seeds. It develops foliage as thickly as space will permit in order that it may secure and digest carbon dioxide in sufficicnl quantity for its needs. An observer taking note of the development of the plant up to its flowering stage, but no further, might think that it developed roots, stalk, branches, leaves and flowers as ends in themselves, but he would be in error ; because these are all only means to an ulterior end — the perpetuation of the species.

As one watches the plant struggling to elaborate its root, branch, leaf and flower systems, he becomes convinced that there are forces within it which continually urge toward a definite objective, often even in the face of serious difficulties. Of course, the plant must use the moisture, the Light and the air in its environment in order to accompHsh its purpose ; but the manner in which and the degree to which these facilities are utilized are determined by the driving forces within the plant. The gardener can assist it by removing the obstacles to the attainment of its aim and by furnishing it with needed materials so that it may accomplish its object without hindrance or diversion or arrest ; but this is all the gardener can do for the plant. He cannot alter its purpose ; he cannot create any forces within it ; he can merely assist it or hinder it in realizing its purpose.

So much by way of introduction. We may now ask — Is the direction which the child takes at every point in his development due to the pressure of internal forces as in the case of the plant, and are his activities dependent upon the interaction of these forces with environmental objects and conditions? Comparing the child when he first comes among us with the bean seed, we note that he is well-nigh infinitely complex. He has an extremely complicated mechanism which suggests that he is designed to engage in exceedingly complex enterprises. In the bean one can with the unaided eye make out all the essential mechanisms, and with the microscope he can observe them in minute detail. But with the child, most of the important mechanisms are hidden from view, and they cannot be examined at all so long as they remain intact in his organism. It is even more true of the child's mental than it is of his physical organism, that it is so complex, even when we first see him, that no one has been able completely to examine or describe it. So it will be understood at the outset that one cannot hope to deal conclusively with all the traits and activities of the individual wliich indicate the directions which the motive forces in his life impel him to take.

One cannot doubt that the motive force first to be manifested in the child's life relates to the maintenance and development of his physical organism. At the moment of birth physical he is equipped with mechanisms which function ef- welfare fectively to keep the body alive ; and not only to keep it ahve, but also to cause it to increase in size, strength and efficiency. Upon the first contact with air the function of breathing is established, and thereafter it proceeds without much if any attention from the individual. Even before birth the heart begins to beat, and throughout life it continues to perform its duties without supervision on the child's part. Before birth, too, the mechanisms concerned in the assimilation of food and the construction of tissues begin to function, and hardly is the child born before he commences to plead for food. During the antenatal period, he secures nutrition without the use of the mouth and accessory equipment, but when he becomes detached from his mother and must secure his nutrition through the mouth, all the acts necessary to convey food to the digestive mechanisms as well as to digest it and convert it into tissues are ready to be performed. The child's sucking and swallowing activities are exceedingly complex, but normally they can be executed at birth with complete success.

As one observes the child during the first weeks he cannot fail to be impressed with the predominance of the activities concerned with the securing and digesting of food. His appeals and protests during the early months have reference to the relief of hunger more largely than to any other need. Whatever he seizes in his hands or whatever touches him on lips or cheeks Predomi- ^e seeks to convey to his mouth. The first sign of nance of awareness of the world about him has reference to

the food-securing his mother as the source of his food. And when he impulse j^^g secured his food he falls asleep and remains asleep while the food is being digested and assimilated. His waking periods during the first three months occur mainly for the purpose of feeding. When he has digested one meal he awakens to secure another. Normally the very young child will not run over his feeding period fifteen minutes without an appeal for food. The impulse to eat is more active than the needs of the body require, as every mother well knows ; the typical child will eat more than he can assimilate. And it is comparatively so easy now to obtain an excess of food that many of the individual's troubles arise out of his uncontrolled impulse to eat. Apparently the impulse was established when food was less abundant and less easily secured than is the case at the present time ; when man had to depend upon what nature in her original state offered him, he had to gorge himself in order to secure enough, because the occasions when he could secure it were relatively infrequent, and such food as he obtained was not highly nutritious. It is as though the child remembered this earlier experience of his ancestors; but he does not take into consideration the changed conditions which make food abundant now and easily secured.

This impulse to eat more than the needs of the body require plays a role from the cradle to the grave. The individual of any age who is relieved from the necessity of muscular toil normally consumes more food than his organism requires for maintenance and efficiency. Many of the ills that afflict mature individuals are due to the impulse to consume food in greater quantities than can be utilized by the organism. This impulse

MOTIVE FORCES LN DEVELOPMENT 7

apparently outlives most other impulses ; the old man enjoys his food after he has ceased to take an interest in much else, and even after nature has destroyed the mechanisms necessary for the proper mastication of food and the ehmination of unused portions. The disharmonies of old age probably arise mainly out of the passion to consume food beyond the measure that it can be utilized in the organism.

It may be mentioned further that social relations have to a considerable degree developed in connection with eating. Eating plays a prominent role in children's parties and in adults' social pastimes. Among primitive people celebrations relate quite largely to feasting; they come together for social purposes when they have secured a supply of food. The chief incitement to social festivities is good fortune in obtaining food. Even among advanced peoples, prominent festivities have relation to prosperity in respect to their crops ; they give thanks to the Giver of Gifts when they have a good harvest, — when their bins are full of corn, their cellars of vegetables and meat, and their larders of flour and fruit.

In human life the impulse to secure food in order to maintain and develop the organism has largely determined the character and degree of development of muscular, nervous and intellectual structures and functions. Keeping this fact in mind it may be asked in passing, — If the individual can secure an abundance of food without the full use of body and mind, will he develop properly and completely? It would unquestionably be an aid to his development if he could not secure food so easily as he often does in these times. The individual who is frequently hungry, or at least who is not surfeited with food will develop a more capable body and more agile mind than one who is never hungry because he is continually satiated. The over-fed child is lethargic in body and dull in mind. Of course, the under- fed child suffers also since he cannot secure nutrition enough to maintain vigorous physical and mental development. But of the two unfortunate conditions, it would probably be to the advantage of the individual in his development to experience a scarcity of food rather than to have a surplus of it. One cannot avoid feeling some concern about the future of a people whose children can secure an abundance of food for the asking, and who are never required to put forth sustained physical effort or to exercise intellectual keenness and accurate judgment in order to obtain food adequate to their needs.

Manifestly the individual could not preserve his organism from annihilation if he did not possess other impulses than Self- those concerned with securing food. In the very be-

protective ginning he must rely upon caretakers to safeguard him from destruction by hostile forces. When he is cold or his clothing is too tight or he is suffering from hunger or colic, he appeals to his mother or nurse for aid. When a loud noise occurs in his vicinity he cries for protection, as though he associated a loud noise with a destructive agent. As he develops, the range of experiences which will cause him to look to his caretakers for protection constantly increases until he gains a large measure of self-reliance. The three-year-old child is likely to be incessantly making appeals to his parents, teacher, or an older brother or sister to shield him from threatened harm, — from lightning and thunder, from strange animals of all sorts and often from famihar animals, even pets, from rough treatment by his playmates, and so on od libitum. At sixteen he normally ceases to ask those about him to safeguard him from harm, for the reason that he has gained confidence in his ability to protect himself. More especially he has learned that the sources of possible harm which harassed him in his earliest years were unreal and so he no longer fears them.

At two, three, or four years of age the child incessantly

MOTIVE FORCES IN DEVELOPMENT g

asks his caretakers to relieve him of pains, whether incurred in his play or arising from within. Even sUght discomfort will cause him to appeal vigorously for aid. Any painful accident or mishap will send him running for rehef to father, mother, teacher, or someone else in whom he has confidence. His alertness in seeking immediate relief from all pain indicates that nature did not wish to take any chances in safeguarding the individual's organism from experiences which might handicap or destroy it. In the course of development this readiness to seek relief from all pain however slight becomes subdued, probably because the individual learns that many of the minor aches and pains and accidents will do no serious injury to his organism and so they may be ignored. Indeed, in time, by the ninth or tenth year as a rule, boys especially cultivate a bravadic indifference to these minor ills and misfortunes. They take pride in being able to endure them without complaint, which was not in any respect true at an earlier age. This fortitude in reaction upon sHght misfortune or minor distress of any sort increases up to maturity, so that the young man or woman may undergo considerable suffering without complaint and without making any attempt to secure relief.

This phenomenon furnishes an illustration of the conflict of driving forces which frequently arises in the course of development. In this instance the individual is conflict of equipped at the outset with the impulse to communi- motive cate every pain, ache or accident to those who may be able to relieve him. But later there awakens an impulse, directly in contrast with the first one, which causes the individual to take pride in bearing his misfortunes stoically, and sometimes deliberately to bring pain upon himself in order that he may show his indifference or superiority to it. In seeking an explanation of this apparent conflict of motive forces, one may suppose that the very young child should freely communicate all his pain and distress since he is unable lo {protect himself from the causes thereof ; but later on when he gains in power of self-protection he may be depended upon to discriminate between the minor and the major sources of danger ; and in his adaptation to his environment it will be of advantage to him to cultivate indifference to all pain of lesser importance. Further, as his organism develops it acquires resistance to hostile agencies which at the outset might destroy it ; and just in the measure that it increases in stability and endurance, the individual may neglect all painful experience of minor consequence because his organism can survive such experience.