How glands affect personality

Most of these cases which have been described, where one single gland is much too active or a great deal too sluggish, would be classified as extreme types of personality. They are, for the most part, definitely normal. Primarily because they are so distinctive it was fairly easy to ascertain just which form of glandular disorder conditioned which kind of mental or physical peculiarity. With personalities which conform more closely to the norm, the question of specific glandular control becomes more baffling. Yet when we note how accurately each specific glandular derangement is correlated with a definite peculiarity of personality, it seems highly probable that slighter variations in individuality may also be due to differences in the endocrin system. When we further realize that any one of the seven glands of internal secretion may be either a little overactive or a little underactive while the rest are normal, or that two or three or four or five glands may be slightly abnormal in one way or another, it begins to appear as though this complicated endocrin system may be responsible for all the lesser variations of personality as well as those which are more pronounced.

An individual whose thyroid is underactive will be different from an individual whose thyroid is overactive, and he will be still more unlike one whose pituitary and adrenals are also exceptionally forceful. Moreover X-ray pictures show that when any one gland is especially small and unable to grow larger in order to compensate for its deficiency, some other gland may expand and in some manner take over its function. So when we come to the study of normal personalities the role of the endocrin system may be much more complex than it is with the simpler and more distinctive glandular types. Our knowledge of the glandular control of the average man is still far from complete, but, remembering the striking symptoms of abnormal functioning, we can discern certain general glandular tendencies among mainly normal types. We cannot as yet say that Mr. Smith’s thyroid is one hundred per cent efficient while his pituitary works only one half as energetically as it should and his adrenals twenty per cent actively. But we can say that from certain physical or mental traits which Mr. Smith shows his whole personality is probably dominated by one or more of his endocrine glands.

If Mr. Smith is exceptionally tall and the bones in his face and hands and feet noticeably large, it is safe to assume that Mr. Smith has a very forceful pituitary body. Yet, if in spite of his height, Mr. Smith appears young for his age, has a smooth boyish face and a youthful outlook on life, then we may correctly infer that his thymus has been active longer than is customary with adults. Mrs. Smith, too, may seem much younger than her chronological age would lead one to expect, and she, also, may have a rudimentary thymus which is continuing to function. But if, as opposed to her husband, she is small and dainty, we would suppose that her pituitary is also smaller than his. And if with her doll-baby stature, she had a still childish mind and was not particularly energetic, we might further conclude that her thyroid was not accomplishing all that it should. If, as she grew older, she became suddenly nervous and irritable, it would seem evident that this gland was suddenly expanding in an attempt to overcome its earlier deficiencies.

Mr. and Mrs. Smith might have two children, a son and a daughter, who while they were young resembled each other rather closely. But as they grew older they might seem more and more different. Perhaps the girl could continue to grow rapidly after she was twelve years of age but would still appear childish. She would still play with her dolls and with younger children and take no interest in the activities which normally absorb the attention of a young girl. Then we would infer that the thymic tendency which she inherited from both parents was intensified in her case. If, however, her other glands were able to overcome this dominance of the thymus and so allow her to achieve adolescence, she might still never become so completely feminine as her mother. She would never be very interested in boys or young men, but would be enthusiastic about athletics and feminist movements. Then it would be reasonable to assume that her adrenal glands had taken over the supremacy once held by the thymus.

The Smith boy, on the other hand, might mature rapidly. He would become quiet and serious at the age when most boys are still playing marbles and hooky. His voice would change and his beard would begin to grow. In this case we could be certain that either his thymus or his pineal gland had deserted him too soon. If he stopped growing at this time it would indicate that his thymus was failing him, but if he continued to become taller and his mind also matured quickly the evidence would be in favor of an atrophying pineal. If later in life he suddenly became exceedingly plump and rather listless, we might conclude that still another gland was not working as hard as it might. This time it would be his pituitary.

These cases are, of course, merely hypothetic and it is entirely too much to expect such a small family to show such divergent types and so many changes in personality. But it does indicate how glandular activity can affect the character and habits of persons who would not be considered abnormal. And taking the population as a whole, certain glandular tendencies do determine definite types of personality. The slow, stupid, colorless people have too little thyroid secretion. Those who are superactive mentally and temperamentally have a large amount of this extract. The very fat or very tall people have extraordinary pituitaries. The energetic, executive types are well supplied with adrenalin. And most of those who seem exceptionally youthful long after they have reached chronological maturity have had thymuses or pineals which have functioned longer than is natural in adult life.