Courage is so closely related to fear and anger that all are always associated in any discussion. Courage is commonly thought of as the emotion that is the opposite of fear. It would follow that courage meant simply inhibition of the adrenal medulla. As a matter of fact, the mechanism of courage is more complex. One must distinguish animal courage and deliberate courage. Animal courage is literally the courage of the beast. As noted, animals with the largest amounts of adrenal cortex are the pugnacious, aggressive, charging kings of the fields and forests. The emotion experienced by them is probably anger with a sort of blood-lust, and no consideration of the consequences. The object attacked acted like the red rag waved at a bull—it had stimulated a flow of the secretion of the adrenal cortex, and the instinct of anger became sparked, as it were, by the new condition of the blood. In courage, deliberate courage, there is more than instinct. There is an act of volition, a display of will. Admitting that without the adrenal cortex such courage would be impossible, the chief credit for courage must be ascribed to the ante-pituitary. It is the proper conjunction of its secretion and that of the adrenal cortex that makes for true courage. So it is we find that acts of courage have been recorded most often of individuals of the ante-pituitary type. Photographs are obtainable of thirty-four winners of the Congressional Medal of Honor for extraordinary bravery in the War with Germany. Of these twenty-three exhibited the somatic criteria or hormonic signs of the ante-pituitary type. A prerequisite for adequate ante-pituitary function is a normal secretion of the interstitial cells of the reproductive glands. Cowardice is said to be a feature of eunuchs.
THE PITUITARY AND INSTINCT
We have seen that, more than any other gland or tissue of the body, the post-pituitary governs the maternal-sexual instincts and their sublimations, the social and creative instincts. A great deal of evidence is in our possession concerning the disturbances of emotion accompanying disturbances of this gland, and controllable by its control. It might be said to energize deeply the tender emotions, and instead of saying soft-hearted we should say much-pituitarized. For all the basic sentiments (as opposed to the intellectualized self-protective sentimentalism), tender-heartedness, sympathy and suggestibility are interlocked with its functions. Its secretion must act upon the great basal ganglia, at the base of the brain, which contain the nerve cells and fibres that are the centers of emotional control and co-ordination.
The ante-pituitary has been depicted as the gland of intellectuality (to use that term for lack of better). By intellectuality we mean the capacity of the mind to control its environment by concepts and abstract ideas. The frontal lobes of the brain are the central offices for higher thought. Their cells are the most complex, have the most numerous branches and association fibres. They store the fruits of abstract thinking, mathematics, for example. The anterior pituitary is in the closest relation and contact with them. Its secretion is tonic to them. Now the instinct that is the forerunner of intellectuality is the instinct of curiosity, with its emotion of wonder, and its expression in the various constructive and acquisitive tendencies. Studies of intellectual men, and of those with a keen instinct of curiosity and a constructive-acquisitive trend prove them to be ante-pituitary dominant in their make-up. The administration of ante-pituitary extract to some defectives increases intellectual activity and self-control. The future of intelligence may expect a great deal from the newer chemistry of the secretions of the ante-pituitary.
Two most important instincts, therefore, which in the complexity of their sublimations have created most of the institutions of society, the maternal and the intellectual, are connected directly with a proper function of the pituitary endocrines. So it happens that disturbances of these instincts, reaching far into the normal and intellectual spheres of the mind, are definitely connected with disturbances of the pituitary. As we shall note in reviewing the essentials of the pituitary-centered or pituito-centric personality, the personality governed by the fluctuations of activity within the pituitary, people with injured, diseased or mechanically limited pituitaries (because of the smallness of the bony case enclosing them) exhibit defects and perversions of conduct and intelligence directly attributable to affections of the very instincts and functions the pituitary governs. Children with small, mechanically cramped pituitaries lie and steal, are bed-wetters, have poor control over themselves, and a low learning capacity.
THE THYROID AND INSTINCT
The chemical mechanism of the instincts described: sex libido, passion and jealousy in relation to the ovaries and testes, fear and anger in relation to the adrenals, sympathy and curiosity in relation to the pituitaries, suggests that a similar explanation will hold for the dynamics of the other instincts. In the closest relation to the thyroid appear the instincts first isolated, so to speak, by McDougall as the instincts of self-display and self-effacement, accompanied by emotions of pride and shame respectively. In certain states of excessive thyroid activity there is an extra stimulation of the instinctive display of the person which may go on to boasting, mania and exhibitionism. On the other hand, in states of thyroid insufficiency, depression is produced, which may go on to melancholia, a desire to be alone, to hide, to sit apart and even a tendency to accuse the self of various uncommitted crimes and sins. In the form of cyclic insanity known as the manic-depressive psychosis, mania alternates with depression, as if the personality were dominated wholly in turn by one or the other of these two instincts of the ego. There is a good deal of evidence that behind them is a corresponding fluctuation in the amount the thyroid secretes into the blood. Among the thyroid-centered attitudes toward the self gyrate more than in any other type. Egomania and megalomania occur most often in thyroid unstable individuals.
ENERGY AND SENSITIVITY
In his classic Inquiries into Human Faculty, Francis Galton laid down some fundamental considerations concerning energy and sensitivity as mental traits. Energy he defined as the capacity for labor, and declared it to be the measure of the fullness of life or vitality. Statistical study by him of men of genius and their ancestors showed them to be endowed with a large amount of energy. It has been said to be the absolute prerequisite of genius. Now if there is a single fact that has been well established by investigations of the internal secretions, it is that the energy quantum of an individual is a function of and determined by his thyroid. The more thyroid he has, the more energetic will he be—the less thyroid the less energetic, and the lazier. The thyroid-centered individual, of the excess thyroid type, actually burns up more food and produces more heat than the ordinary organism. He burns himself up faster in general.
When the thyroid sends more secretion into the blood, more thyroxin, it accelerates all the functions and activities of the organs. Tea and coffee produce loquacity because they stimulate the thyroid. People with thyroid dominant constitutions talk fluently, rapidly, and continuously. Their energy makes them doers, actors rather than spectators. They get up early in the morning, are on the go all day without surcease or fatigue, go to bed late, and often suffer from insomnia.