The adrenal glands, however, are primarily the glands of combat. They produce that immediate and active response which men exhibit in times of danger or anger, and their secretion is stimulated in times of emergency. Pain, rage and fear have a definite effect upon the discharge, and we are told,

"all the evidence points to its medulla as the secretor of the substance which makes for the phenomena of fear, and to its cortex as dominant in the reactions of anger."
- Berman, Louis, M.D., The Glands Regulating Personality, p. 76.

Also: "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 a 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 [50] 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."
- Berman, Louis, M.D., The Glands Regulating Personality, p. 177.