The Glands Regulating Personality Part 25

The conception of a particular chemical make-up of the individual, statable and relatively controllable in terms of the internal secretions, supplies a more rational and satisfactory method of approach to the problem than any so far suggested as far as vertebrates are concerned at any rate. In effect, the differences between individuals may fundamentally thus be grouped among the differences which distinguish other chemical substances. The difference between water, technically known as hydrogen monoxide, and the antiseptic fluid labeled hydrogen dioxide lies wholly in the possession by the latter of an extra atom of oxygen in its molecules.

All the peculiarities and qualities by which hydrogen peroxide is separated from water are referred to that additional quantum of oxygen. So the diversity of const.i.tution and appearance of two brothers, alike in that they have inherited the same internal secretion trends, may be traced to the superiority of the pituitary of the one over the other.

Variation and resemblance are large issues, crucial material of the science of biology upon which much has been thought and written. That the proportion of the endocrines determines variation and resemblance, heredity and evolution is a hypothesis advanced, supported by a large amount of facts, and capable of the most interesting experimental verification and observation. If a child resembles particularly either of its parents, grandparents or relatives, there is good reason for believing that it is because their endocrine formulas are very much alike. When people apparently not blood-related at all resemble one other, the same law must hold. Resemblances may be partial or complete, and the degree will depend upon the amount and ratio of the internal secretions involved.

The same endocrine const.i.tutions will produce corresponding physiques, physiognomies, abilities and characters. Deviations in endocrine type from that of the original stock, more of one endocrine and less of another, is at the bottom of the phenomenon of variation, basic for the origin of new species as well as the extinction of the old. In short, viewing the internal secretions as determinants, by their quant.i.tative variations, of a host of biologic phenomena furnishes a concrete and detailed foundation for Darwin's theory of pangenesis.

INHERITANCE OF ACQUIRED CHARACTERS

Darwin's theory of pangenesis was an attempt to harmonize everything known in his time about heredity. It supposed that the various organs of the body gave off into the blood substances, themselves in miniature, which were taken up by the s.e.x cells, and so became responsible for the development of their mother-organ in the newly forming individual. Modern knowledge cannot accept all this as a whole. But in a modified version, it has become the germ of a theory of heredity of which J.T. Cunningham, of Oxford, is the chief backer.

Beginning with the traits and qualities which distinguish the s.e.xes, grouped as the secondary s.e.x characters, he showed that they are correlated with the special s.e.xual function of the species in which they occur. These traits appear only when the hormones occur which are present in one s.e.x and that only when the gonads of that s.e.x are mature. In some cases they appear only at the period of the year when reproduction takes place, disappearing again after the breeding season. Their presence makes certain cells develop in excessive numbers at a particular spot in the organism (as in the growth of b.r.e.a.s.t.s from a few sweat glands) or causes them to specialize (to make hair on the face in man, or to grow antlers on the head of a stag).

After castration, the hormones being absent, all these points of contrast between the s.e.xes fail to appear. So by a.n.a.logy we may explain all somatic and psychic differentiation as functions of the glands of internal secretion. Contemplated from the angle of the effect of environment upon the endocrines, and a reflected action upon the germ cells, we may outline a mechanism of the inheritance of acquired characters at certain times and consequent adaptation. The cycle of events would be as follows:

1. A state of lability of cells at a point because of increased or decreased use.

2. An increased or decreased appropriation by them of the hormone controlling their function.

3. A corresponding increase or decrease in function of the gland of internal secretion and so,

4. An increased or decreased representation of it in the reproductive s.e.x cells in the gonads.

To take a cla.s.sic ill.u.s.tration, the long neck of the giraffe. The neck of certain animals living in a district populated by trees with high branches would be in state of instability. If at the same time the pituitary, for some reason, was unstable and reacted with an extra supply of its secretion, it would stimulate the neck cells to reproduce themselves. In turn the pituitary would become stabilized in the direction of increased secretion, and hand on the component of increased secretion to the s.e.x cells. That component, in conjunction with other factors, would therefore determine the emergence of a definite species character. In other words, the glands of internal secretion, as intermediaries between the environment and body, and between the body and the reproductive s.e.x cells or germplasm, tender the clue to a phase of the puzzle of heredity, adaptation and evolution. It is only a dotted outline of an explanation to be sure, but one certainly capable of being filled in.

THE BEARING ON BREEDING

Since the endocrine glands are so subtly sensitive and responsive to environment, and are at the same time so intimately concerned in the process of inheritance--a law which sums up their influence upon resemblance and variation in animals--there is no need to stress their importance for the practical science and art of good breeding, eugenics. Another mode of approach to its problems is opened up, and fresh enthusiasm instilled into its hopes and aspirations. A method of a.n.a.lysis of the factors involved, together with rules for the prediction of the outcome of certain matings, when finally worked out, will elevate its procedure to the level of the more exact sciences.

A man's chief gift to his children is his internal secretion composition. The endocrines are truly the matter of breeding as they are of growth. They are the material carriers of the inherited physical and psychic dispositions, powers, abilities and disabilities from the soma to the germplasm and back from the germplasm to the soma. All kinds of questions arise as soon as one attempts to consider the bearing of this underlying principle upon concrete situations.

What happens, say, when a pituitocentric mates with a thyrocentric?

Or when a pituitocentric marries a pituitocentric? Is there a reinforcement or a cancellation of the dominant endocrine? Is there a quant.i.tative addition of internal glandular tendencies in the germplasm, or a more complex rearrangement dependent upon reactions between all the internal secretions?

The term endocrine dominants brings up the inquiries of Mendelism, and the relation of Mendelian conceptions of dominant and recessive to the internal secretions. The Mendelians have emphasized the role of the unit factor in heredity, and the conservation of the unit factor as an ent.i.ty through all the adventures of matings. Also, that when unit factors, say of the color of the eyes, come into conflict, brown or black being mixed with blue or grey, one, the recessive, is submerged and overlaid but not destroyed by the other, the dominant. So brown or black eyes, dark hair, curly hair, dark skin, and so on, are dominant, while blue or grey eyes, light or straight hair, light skin are recessives. A nervous temperament is dominant to the phlegmatic. A number of psychic qualities have been declared to be Mendelian unit factors: memory, mechanical instinct, mathematical ability, literary ability, musical ability, and even handwriting.

As architects of human qualities the endocrines must be involved in the Mendelian unit factors. Moreover, they seem to act upon a particular locale in different degrees, which is the strongest argument against the resolution of a number of structural traits into Mendelian unit characters. Most characters, somatic or psychic, are the products not of the action of one internal secretion alone, but of the interlinked activities of all of them. The amount of fat deposited under the skin, for instance, is influenced by the pituitary, the thyroid, the pancreas, the liver, the adrenals and the s.e.x glands.

Other qualities, likewise, are resultants of a compromise between all the endocrine factors comprising the equation of the individual. If we are to look for unit factors at all in endocrine heredity, we must look more deeply into const.i.tution, and measure the hormone potentials and their mobilization or suppression.

It will, in all probability, be found that the stability or instability of an endocrine will have a good deal to do with the part played by it in inheritance as well as in the life of the individual An unstable pituitocentric marrying another unstable pituitocentric will have children either exceptionally small or tall, or abnormally bright or stupid. The instability tends to right itself in the next generation, or that following. Genius as a sport, as well as sudden degeneration of family stock, the whole problem of mutation, may be closely connected with this tendency.

It has been noted that the extinction of species has been preceded by a great increase in their size, for example, the case of the great reptilia of prehistoric time. That possibly represented pituitary stabilization, and so an abeyance of the ability to vary, necessary for fresh adaptation to a changing environment. Indeed, endocrine instability appears the fundamental condition of the tendency to vary, endocrine stability the opposite.

Certain endocrine facts in relation to heredity should be mentioned.

The daughters of mothers who menstruated early, themselves menstruate early. Animals fed upon thyroid during pregnancy, comparable to the thyrocentric, give birth to offspring with a very large thymus, comparable to the thymocentric. Women with partial thyroid deficiency, or myxedema, bear cretins. These are suggestive of what the internal secretions may do to an individual in inheritance and development.

Inherited endocrine potential is the maximum reaction of which a gland is capable. This matter of potential is comparable to the factor of reserve power or margin of safety demonstrated up to the hilt for such organs as the heart and kidney as varying from individual to individual. A low potential, like instability of an internal secretion gland, may be latent, and not made manifest until the proper stimulus, the maximum amount of stress and strain, like accident, disease, shock or war, arrives.

When the individual is tested the effects may be purely local because there is always in the organism a point of least resistance. Physical changes alone may be prominent. Or because somatic changes are minor, the psychic will dominate the picture. An attack of the "blues,"

unaccompanied by any demonstrable transformation of the bodily processes, may be the sole symptom of an endocrine failure somewhere in the chain due to hereditary weakness or low potential.

So we may account for family trends and streaks, for varieties and strains among individuals, upon more precise lines based upon endocrine a.n.a.lysis. Family disturbances of the internal secretions of the extreme sort denominated disease are well known. Indeed, a number of family diseases or predispositions to diseases, have been traced to them. Predisposition in any direction will probably be shown to be caused by them, within limits. Research here has its opportunity.

THE IMPROVEMENT OF RACIAL STOCK

A vast new territory of inquiry and achievement, as yet totally unexplored, is opened by the endocrines to the eugenists, and those idealists whose most earnest aspiration is the improvement of racial stock as a necessary preliminary to improvement of racial life.

Beginning with Galton, they have brought to light a great collection of data to prove that human traits and faculties, good and bad, are inherited. Ability has been shown to run in certain families and degeneracy in others. Yet all of the practical net result has been summed up in the term "negative eugenics," the eugenics of prohibition and warning.

Now the concept of personality, as woven around a system of chemical reflexes, handed on from generation to generation, is bound to change all that, and to create a structure of positive eugenics. It has been said that what radium is to chemistry, the internal secretions are to physiology. Just as radium enlightens the chemist about the history of matter, and the integrations and disintegrations const.i.tuting the life of an element--the internal secretions illuminate the history of the individual as part of the life of the race, and of its integrations and disintegrations. Seeing the individual as a system of chemical substances interacting will a.s.sist enormously to predict the nature, character and const.i.tution of his descendants, which is essentially what the eugenist is after.

The study of matings, the heart of the matter, will concern itself with the investigation and comparison of the kind of endocrine personalities that mate, the internal secretion predominances that cross, and the consequent endocrine personality of the offspring.

Data bearing upon physique and physiognomy, details of anatomy and function, mind and behaviour will so be co-ordinated as no eugenist has. .h.i.therto succeeded in doing. Laws of endocrine inheritance will emerge that will bring the control of heredity within measurable distance. Standards and norms of a new kind would be obtained.

A beginning of this study of endocrine inheritance, on the pathologic side, has been made. Some of these have been along Mendelian lines.

Following up abnormal growth (making giants and dwarfs) and abnormal metabolism (goitre, diabetes, and so on), it has been stated that it would seem that abnormal growth is dominant in the male, and recessive in the female, while abnormal metabolism is dominant in the female and recessive in the male. If an endocrine abnormality like a goitre, or cretinism, or a dwarf or giant appear in a family as a sign of endocrine instability, other members of that family will very likely show internal secretion abnormalities.

If one gland of internal secretion acts as the centre of the system and the others as satellites, we should be able to trace what happens to it in the different generations. Does it maintain its supremacy? Or will it be ousted by another member of the group? The time will come when we shall thus be able to advise prospective parents of the consequences of procreation and to forecast the meaning for the race of a particular marriage. Internal glandular a.n.a.lysis may become legally compulsory for those about to mate before the end of the present century.

What are desirable and undesirable matings? The general law followed by nature in her helterskelter way seems to be the production of the greatest number of hybrids and variations possible, whether for good or evil does not matter. Certain endocrine types appear to be specially attracted to others belonging to the same group. Thus thymus-centered types frequently marry. The ante-pituitary type of male, the strongly masculine, mates often with the post-pituitary type of female, the markedly feminine. The children exhibit the lineaments of the pituitary-centered type. The general trend seems to be the establishment of a better balanced, equilibrated type. Yet the children often are apt to segregate into pituitary dominants or pituitary deficients. Happiness and unhappiness in marriage should be examined from the standpoint of endocrine compatibility or incompatibility. Likewise those divorced or about to be divorced.

The correction of endocrine defects, disturbances, imbalances and instabilities, before mating, presents another field. It remains to be seen whether we shall thereby, in one generation, be able to affect at all the germplasm, hitherto revered by all pious biologists as an environment-proof holy of holies. No one can deny, in the face of the mult.i.tude of evidence available, that internal secretion disturbances occur in the mother, which, when grave, offer in the infant gross proof of their significance, and therefore when slight must more subtly work upon it. Endocrine disturbances in infancy have been traced to endocrine disturbances in the mother during pregnancy.

Pregnant animals fed on thyroid give birth to young with large thymus glands. The diet of the mother has been proved conclusively to influence the development and const.i.tution of the child. As the internal secretions influence the history of the food in the body, they affect development in the womb indirectly as well as directly.

Certainly, whether or no we learn how to change the nature of germplasm within a short time, we have in the endocrines the means at hand for affecting _the whole individual that is born and sees the light of day_.

THE CONTROL OF MUTATIONS

The true physical and intellectual evolution of man depends upon the production of mutations of a desirable kind that can survive. The information furnished by the study of the endocrines concerning the genesis of personality provides the foundations for a positive eugenics, a eugenics of the encouragement of desirable matings, with the proper legal and social procedures. Selective breeding for the production of the best endocrine types should become practicable.

But the biologist should be able to go farther. If the eugenist is to limit himself to the method of the animal breeder he will have to rest satisfied with the characters or hereditary factors given, that turn up spontaneously in an individual. But with the internal secretions as the controllable controllers of mutations, the outlook changes.

It should become possible to produce new mutations, good and bad, to speed up their production at any rate. The feeding of thyroid to a gifted father before procreation might enhance immeasurably the chances of transmission of his gift as well as of its intensification in his offspring. A field of investigation is opened that would embrace in due time the deliberate control of human evolution.

All the physical traits, stature, color, muscle function, and so on, offer themselves for improvement, as well as brain size, and the intellectual and emotional factors which have dominated man's social evolution. The general prevalence of nervous disorders in civilized countries, visible even in the nervous infants the specialist in children's diseases is called upon to treat, shows that the nervous system of the better part of mankind is in a state of unstable equilibrium. It may be another example of the curious coincidences that have been called the Fitness of the Environment that the investigation of the endocrines promises to put into our hands the instruments of the control of the future of the nervous system. In general, meanwhile, the eugenist should strive for raising the level of the endocrine potential, and discourage its lowering. That means the encouragement of matings in which all the internal secretion activities are reinforced. On the other hand, those internal secretion combinations, generally leading to a deficiency of all of them which produce types of mental defectives, delinquency and crime should not be allowed to occur.

THE INFLUENCE OF ENVIRONMENT

What suggestions now are there for the euthenist who would control the influence of environment upon child culture. There are certain pertinent facts and leads that are worth considering.

In a.n.a.lyzing environment, one must distinguish sharply in the jungle, the non-living factors from the living. For while the nonliving act upon the endocrines directly, the living act upon the vegetative system, as a whole. The non-living factors are those with the intimate scrutiny of which physics and chemistry have busied themselves: food, water, air, light, heat, electricity, magnetism. The living are the animals that prowl all over the planet, the predatories spreading the gospel of fear.

The dietetic habits of a person, for instance, are known to have an influence upon the glands of internal secretion. Meat-eating produces a greater call upon the thyroid than any other form of food. In time this ought to produce a degree of hyperthyroidism in the carniverous populations. Pre-war statistics concerning meat-eating in different countries show the greatest meat-eating among the English-speaking groups, who all in all must be admitted the most energetic.

_Meat per Day per_ _Countries_ _Capita in Grams_

Australia 306 U.S. of America 149 Great Britain 130 France 92 Belgium and Holland 86 Austria-Hungary 79 Russia 59 Spain 61 Italy 29 j.a.pan 25

Sea-water contains iodine. People living in contact with sea-water would be apt to get more iodine in their systems, and so a greater degree of thyroid activity. On the other hand, certain bodies and sources of inland water hold something deleterious to the thyroid, so that whole populations in Europe, Asia and America drinking such water have become goitrous and cretinous, and a large percentage straight imbeciles. Endemic cretinism is the name given to the condition. In parts of Switzerland, Savoy, Tyrol and the Pyrenees, in America around some of the Great Lakes, there are still such foci. Marco Polo described similar areas he encountered in his travels through Asia.

Certain foods with aphrodisiac qualities may act by stimulating the internal secretion of the s.e.x glands. A type of pituitocentric has an almost uncontrollable craving for sweets. Alcohol and the endocrines remain to be studied.

Light, heat and humidity stand in some special relation to the adrenals. Pigment deposit in the skin as protection against light is controlled by the adrenal cortex. The reaction of the skin blood vessels to heat and humidity is regulated by the adrenal medulla. A change in the adrenal as a response to changes of temperature and humidity in an environment would result in a number of concomitant transformations throughout the body. So variation and adaptation are probably connected. Most Europeans living for a sufficiently long time in the tropics suffer from a combination of symptoms spoken of as "Punjab head" or "Bengal head." The condition is probably the result of excessive adrenal stimulation by the excessive heat and light of the tropical sun, followed by a reaction of exhaustion and failure, with the consequent phenomena of a form of neurasthenia. In the section on the pineal gland there was mentioned the relation between light and the pineal gland in growing animals, and how it serves to keep in check the s.e.x-stimulating action of light. The earlier p.u.b.erty and menstruation of the warmer climates may be explained as due to an earlier regression of the pineal under the pressure of a great amount of light playing upon the skin.

All these, and many more could be cited, are instances of the direct influence of environmental factors upon one or more of the endocrines, and so upon the organism as a whole. Indeed, stimuli may be considered to modify an organism only in so far as they modify the glands of internal secretion. Consequently, climatic factors will tend to make a population possess certain points of resemblance in common.