In which we find a goodly inheritance
THE STORY OF THE INSTINCTS
Each in His Own Tongue
A fire mist and a planet,
A crystal and a cell,
A jelly-fish and a saurian,
And caves where cavemen dwell;
Then a sense of law and beauty,
And a face turned from the clod;
Some call it evolution
And others call it God. 
If we begin at the beginning, we have to go back a long way to get our start, for the roots of our family tree reach back over millions of years. "In the beginning—God." These first words of the book of Genesis must be, in spirit at least, the first words of any discussion of life. We know now, however, that when God made man, He did not complete His masterpiece at one sitting, but instead devised a plan by which the onward urge within and the environment without should act and interact until from countless adaptations a human being was made.
William Herbert Carruth.
As the late Dr. Putnam of Harvard University says, "We stand as the representative of a Creative Energy that expressed itself first in far simpler forms of life and finally in the form of human instincts."  And again: "The choices and decisions of the organisms whose lives prepared the way through eons of time for ours, present themselves to us as instincts." 
Putnam: Human Motives, p. 32.
Putnam: Human Motives, p. 18.
Introducing the Instincts
Back of Our Dispositions. What is it that makes the baby jump at a noise? What energizes a man when you tell him he is a liar? What makes a young girl blush when you look at her, or a youth begin to take pains with his necktie? What makes men go to war or build tunnels or found hospitals or make love or save for a home? What makes a woman slave for her children, or give her life for them if need be? "Instinct" you say, and rightly. Back of every one of these well-known human tendencies is a specific instinct or group of instincts. The story of the life of man and the story of the mind of man must begin with the instincts. Indeed, any intelligent approach to human life, whether it be that of the mother, the teacher, the preacher, the social worker or the neurologist, leads back inevitably to the instincts as the starting-point of understanding. But what is instinct?
We are apt to be a bit hazy on that point, as we are on any fundamental thing with which we intimately live. We reckon on these instinctive tendencies every hour of the day, but as we are not used to labeling them, it may help in the very beginning of our discussion to have a list before our eyes. Here, then, is a list of the fundamental tendencies of the human race and the emotions which drive them to fulfilment.
THE SPECIFIC INSTINCTS AND THEIR EMOTIONS (AFTER MCDOUGALL)
Positive Self-feeling (Elation)
Negative Self-feeling (Subjection)
Love of Possession
These are the fundamental tendencies or dispositions with which every human being is endowed as he comes into the world. Differing in degree in different individuals, they unite in varying proportions to form various kinds of dispositions, but are in greater or less degree the common property of us all.
There flows through the life of every creature a steady stream of energy. Scientists have not been able to decide on a descriptive term for this all-important life-force. It has been variously called "libido," "vital impulse" or "élan vital," "the spirit of life," "hormé," and "creative energy." The chief business of this life-force seems to be the preservation and development of the individual and the preservation and development of the race. In the service of these two needs have grown up these habit-reactions which we call instincts. The first ten of our list belong under the heading of self-preservation and the last two under that of race-preservation. As hunger is the most urgent representative of the self-preservative group, and as reproduction and parental care make up the race-preservative group, some scientists refer all impulses to the two great instincts of nutrition and sex, using these words in the widest sense. However, it will be useful for our purpose to follow McDougall's classification and to examine individually the various tendencies of the two groups.
In Debt to Our Ancestors. An instinct is the result of the experience of the race, laid in brain and nerve-cells ready for use. It is a gift from our ancestors, an inheritance from the education of the age-long line of beings who have gone before. In the struggle for existence, it has been necessary for the members of the race to feed themselves, to run away from danger, to fight, to herd together, to reproduce themselves, to care for their young, and to do various other things which make for the well-being or preservation of the race. The individuals that did these things at the right time survived and passed on to their offspring an inherited tendency to this kind of reaction. McDougall defines an instinct as "an inherited or innate psycho-physical disposition which determines its possessor to perceive or pay attention to objects of a certain class, to experience an emotional excitement of a particular quality upon perceiving such an object, and to act in regard to it in a particular manner, or at least to experience an impulse to such action." This is just what an instinct is,—an inherited disposition to notice, to feel, and to want to act in certain ways in certain situations. It is the something which makes us act when we cannot explain why, the something that goes deeper than reason, and that links us to all other human beings,—those who live to-day and those who have gone before.
It is true that East is East and West is West, but the two do meet in the common foundation of our human nature. The likeness between men and between races is far greater and far more fundamental than the differences can ever be.
Firing Up the Engine. Purpose is writ large across the face of an instinct, and that purpose is always toward action. Whenever a situation arises which demands instantaneous action, the instinct is the means of securing it. Planted within the creature is a tendency which makes it perceive and feel and act in the appropriate way. It will be noticed that there are three distinct parts to the process, corresponding to intellect, emotion, will. The initial intellectual part makes us sensitive to certain situations, makes us recognize an object as meaningful and significant, and waves the flag for the emotion; the emotion fires up the engine, pulls the levers all over the body that release its energy and get it ready for action, and pushes the button that calls into the mind an intense, almost irresistible desire or impulse to act. Once aroused, the emotion and the impulse are not to be changed. In man or beast, in savage or savant, the intense feeling, the marked bodily changes, and the yearning for action are identical and unchangeable. The brakes can be put on and the action suppressed, but in that case the end of the whole process is defeated. Could anything be plainer than that an instinct and its emotion were never intended to be aroused except in situations in which their characteristic action is to be desired? An emotion is the hot part of an instinct and exists solely for securing action. If all signs of the emotion are to be suppressed, all expression denied, why the emotion?
But although the emotion and the impulse, once aroused, are beyond control, there is yet one part of the instinct that is meant to be controlled. The initial or receptive portion, that which notices a situation, recognizes it as significant, and sends in the signal for action, can be trained to discrimination. This is where reason comes in. If the situation calls for flight, fear is in order; if it calls for fight, anger is in order; if it calls for examination, wonder is in order; but if it calls for none of these things, reason should show some discrimination and refuse to call up the emotion.
The Right of Way. There is a law that comes to the aid of reason in this dilemma and that is the "law of the common path."  By this is meant that man is capable of but one intense emotion at a time. No one can imagine himself strenuously making love while he is shaken by an agony of fear, or ravenously eating while he is in a passion of rage. The stronger emotion gets the right of way, obtains control of mental and bodily machinery, and leaves no room for opposite states. If the two emotions are not antagonistic, they may blend together to form a compound emotion, but if in the nature of the case such a blending is impossible, the weaker is for the time being forgotten in the intensity of the stronger. "The expulsive power of a new affection" is not merely a happy phrase; it is a fact in every day life. The problem, then, resolves itself into ways of making the desirable emotion the stronger, of learning how to form the habit of giving it the head start and the right of way. In our chapter on "Choosing the Emotions," we shall find that much depends on building up the right kind of sentiments, or the permanent organization of instincts around ideas. However, we must first look more closely at the separate instincts to acquaint ourselves with the purpose and the ways of each, and to discover the nature of the forces with which we have to deal.
Sherrington: Integrative Action of the Nervous System.
I The Self-Preservative Instincts
Hunger. Hunger is the most pressing desire of the egoistic or self-preserving impulse. The yearning for food and the impulse to seek and eat it are aroused organically within the body and are behind much of the activity of every type of life. As the impulse is so familiar, and its promptings are so little subject to psychic control, it seems unnecessary to do more than mention its importance.
Flight and Fear. All through the ages the race has been subject to injury. Species has been pitted against species, individual against individual. He who could fight hardest or run fastest has survived and passed his abilities on to his offspring. Not all could be strongest for fight, and many species have owed their existence to their ability to run and to know when to run. Thus it is that one of the strongest and most universal tendencies is the instinct for flight, and its emotion, fear. "Fear is the representation of injury and is born of the innumerable injuries which have been inflicted in the course of evolution."  Some babies are frightened if they are held too loosely, even though they have never known a fall. Some persons have an instinctive fear of cats, a left-over from the time when the race needed to flee from the tiger and others of the cat family. Almost every one, no matter in what state of culture, fears the unknown because the race before him has had to be afraid of that which was not familiar.
Crile: Origin and Nature of the Emotions.
The emotion of fear is well known, but its purpose is not so often recognized. An emotion brings about internal changes, visceral changes they are called, which enable the organism to act on the emotion,—to accomplish its object. There is only so much energy available at a given moment, stored up in the brain cells, ready for use. In such an emergency as flight every ounce of energy is needed. The large muscles used in running must have a great supply of extra energy. The heart and lungs must be speeded up in order to provide oxygen and take care of extra waste products. The special senses of sight and hearing must be sensitized. Digestion and intestinal peristalsis must be stopped in order to save energy. No person could by conscious thought accomplish all these things. How, then, are they brought about?
Internal Laboratories. In the wonderful internal laboratory of the body there are little glands whose business it is to secrete chemicals for just these emergencies. When an object is sighted which arouses fear, the brain cells flash instantaneous messages over the body, among others to the supra-renal glands or adrenals, just over the kidneys, and to the thyroid gland in the neck. Instantly these glands pour forth adrenalin and thyroid secretion into the blood, and the body responds. Blood pressure rises; brain cells speed up; the liver pours forth glycogen, its ready-to-burn fuel; sweat-glands send forth cold perspiration in order to regulate temperature; blood is pumped out from stomach and intestines to the external muscles. As we have seen, the body as a whole can respond to just one stimulus at a time. The response to this stimulus has the right of way. The whole body is integrated, set for this one thing. When fear holds the switchboard no other messages are allowed on the line, and the creature is ready for flight.
But after flight comes concealment with the opposite bodily need, the need for absolute silence. This is why we sometimes get the opposite result. The heart seems to stop beating, the breath ceases, the limbs refuse to move, all because our ancestors needed to hide after they had run, and because we are in a very real way a part of them.
Old-Fashioned Fear. There is one passage from Dr. Crile's book which so admirably sums up these points that it seems worth while to insert it at length.
We fear not in our hearts alone, not in our brains alone, not in our viscera alone—fear influences every organ and tissue. Each organ or tissue is stimulated or inhibited according to its use or hindrance in the physical struggle for existence. By thus concentrating all or most of the nerve force on the nerve-muscular mechanism for defense, a greater physical power is developed. Hence it is that under the stimulus of fear animals are able to perform preternatural feats of strength. For the same reason, the exhaustion following fear will be increased as the powerful stimulus of fear drains the cup of nervous energy even though no visible action may result.... Perhaps the most striking difference between man and animals lies in the greater control which man has gained over his primitive instinctive reactions. As compared with the entire duration of organic evolution, man came down from his arboreal abode and assumed his new rôle of increased domination over the physical world but a moment ago. And now, though sitting at his desk in command of the complicated machinery of civilization, when he fears a business catastrophe his fear is manifested in the terms of his ancestral physical battle in the struggle for existence. He cannot fear intellectually, he cannot fear dispassionately, he fears with all his organs, and the same organs are stimulated and inhibited as if, instead of its being a battle of credit, or position, or of honor, it were a physical battle with teeth and claws.... Nature has but one means of response to fear, and whatever its cause the phenomena are always the same—always physical. 
Crile: Origin and Nature of the Emotions, p. 60 ff.
The moral is as plain as day: Learn to call up fear only when speedy legs are needed, not a cool head or a comfortable digestion. Fear is a costly proceeding, an emergency measure like a fire-alarm, to be used only when the occasion is urgent enough to demand it. How often it is misused and how large a part it plays in nervous symptoms, both mental and physical, will appear more clearly in later chapters.
Repulsion and Disgust. Akin to the instinct of flight is that of repulsion, which impels us, instead of fleeing, to thrust the object away. It leads us to reject from the mouth noxious and disgusting objects and to shrink from slimy, creepy creatures, and has of course been highly useful in protecting the race from poisons and snakes. It still operates in the tendency to put away from us those things, mental or physical, toward which we feel aversion or disgust. Recent psychological discoveries have revealed how largely a neurosis consists in putting away from us—out of consciousness,—whatever we do not wish to recognize, and so it happens that disgust plays an unexpected part in nervous disorders.
Curiosity and Wonder. Fortunately for the race, it has not had to wait until different features of the environment prove to be helpful or harmful. There is an instinct which urges forward to exploration and discovery and which enables the creature not only to adapt itself to the environment but to learn how to adapt the environment to itself. This is the instinct of curiosity. It is the impulse back of all advance in science, religion, and intellectual achievement of every kind, and is sometimes called "intellectual feeling."
Self-Assertion. It goes almost without saying that one of the strongest and most important impulses of mankind is the instinct of self-assertion; it often gets us into trouble, but it is also behind every effort toward developed character. At its lowest level self-assertion manifests itself in the strutting of the peacock, the prancing of the horse, and the "See how big I am," of the small boy. At its highest level, when combined with self-consciousness and the moral sentiments acquired from society and developed into the self-regarding sentiment, it is responsible for most of our ideas of right, our conception of what is and what is not compatible with our self-respect.
Self-Abasement. Self-assertion is aroused primarily by the presence of others and especially of those to whom we feel in any way superior, but when the presence of others makes us feel small, when we want to hide or keep in the background, we are being moved by the opposite instinct of self-abasement and negative self-feeling. It may be either the real or the fancied superiority of the spectators that arouses this feeling,—their wisdom or strength, beauty or good clothes. Sometimes, as in stage-fright, it is their numerical superiority. Bashfulness is the struggle between the two self-instincts, assertion and abasement. Our impulse for self-display urges us on to make a good impression, while our feeling of inferiority impels us to get away unnoticed. Hence the struggle and the painful emotion.
Gregariousness. Man has been called a gregarious animal. That is, like the animals, he likes to run with his kind, and feels a pronounced aversion to prolonged isolation. It is this "herd-instinct," too, which makes man so extremely sensitive to the opinions of the society in which he lives. Because of this impulse to go with the crowd, ideas received through education are accepted as imperative and are backed up by all the force of the instinct of self-regard. When the teachings of society happen to run counter to the laws of our being, the possibilities of conflict are indeed great. 
For a thorough discussion of the importance of this instinct, see Trotter's Instincts of the Herd in Peace and War.
Acquisition. Another fundamental disposition in both animals and men is the instinct for possession, the instinct whose function it is to provide for future needs. Squirrels and birds lay up nuts for the winter; the dog hides his bone where only he can find it. Children love to have things for their "very own," and almost invariably go through the hoarding stage in which stamps or samples or bits of string are hoarded for the sake of possession, quite apart from their usefulness or value. Much of the training of children consists in learning what is "mine" and what is "thine," and respect for the property of others can develop only out of a sense of one's own property rights.
Construction. There is an innate satisfaction in making something,—from a doll-dress to a poem,—and this satisfaction rests on the impulse to construct, to fashion something with our own hands or our own brain. The emotion accompanying this instinct is too indefinite to have a name but it is nevertheless a real one and plays a large part in the sense of power which results from the satisfaction of good work well done. Later it will be seen how closely related is this impulse to the creative instinct of reproduction and how useful it can be in drawing off the surplus energy of that much denied instinct.
Pugnacity and Anger. What is it that makes us angry? A little thought will convince us that the thing which arouses our fury is not the sight of any special object, but the blocking of any one of the other instincts. Watch any animal at bay when its chance for flight has gone. The timidest one will turn and fight with every sign of fury. Watch a mother when her young are threatened,—bear, or cat or lion or human. Fear has no place then. It is entirely displaced by anger over the balking of the maternal instinct of protection. Strictly speaking, pugnacity belongs among the instincts neither of self-preservation nor of race-preservation, but is a special device for reinforcing both groups.
As fear supplies the energy for running, so anger fits us for fight,—and for nothing but fight. The mechanism is almost identical with that of fear. Brain and liver, adrenals and thyroid are the means, but the emotion presses the button and releases the energy, stopping all digestion and energizing all combat-muscles. The blood is flooded with fuel and with substances which, if not used, are harmful to the body. We were never meant to be angry without fighting. The habit of self-control has its distinct advantages, but it is hard on the body, which was patterned before self-control came into fashion. The wise man, once he is aroused, lets off steam at the woodpile or on a long, vigorous walk. He probably does not say to himself that he is a motor animal integrated for fight and that he must get rid of glycogen and adrenalin and thyroid secretion. He only knows that he feels better "on the move."
The wiser man does not let himself get angry in the first place unless the situation calls for fight. However, the fight need not be a hand-to-hand combat with one's fellow man. William James has pointed out that there is a "moral equivalent for war," and that the energy of this instinct may be used to reinforce other impulses and help overcome obstacles of all sorts. A good deal of the business man's zest, the engineer's determination, and the reformer's zeal spring from the fight-instinct used in the right way. As James, Cannon, and others have pointed out, the way to end war may be to employ man's instinct of pugnacity in fighting the universal enemies of the race—fire, flood, famine, disease, and the various social evils—rather than let it spend its force in war between nations. Even our sports may be offshoots of the fight-instinct, for McDougall holds that the play-tendency has its root in the instinct of rivalry, a modified form of pugnacity. Evidently fighting-blood is a useful inheritance, even to-day, and rightly directed is a necessary part of a complete and forceful personality.
This, then, completes the list of self-preservative instincts, those which are commonly called egoistic and which have been given us for the maintenance of our own individual personal lives. But our endowment includes another set of impulses which are no less important and which must be reckoned with if human conduct is to be understood.