Heredity

“ Ribot, Heredity, 1—“Heredity is that biological law by which all beings endowed with life tend to repeat themselves in their descendants; it is for the species what personal identity is for the individual. ”

“ In this chapter we shall consider the significance of heredity and environment in their relation to character.
§ 2. Physical Heredity. All character has a physical basis. Every child has a body, and without a body it could have no character. In studying the development of character, we must therefore first examine the meaning of physical heredity. Heredity has been defined as the genetic relation that binds one generation to another. The individual's inheritance includes all that he is, or has, to start with, in virtue of this genetic relation. ”

“ HEREDITY AND PREEXISTENCE 1 THE law of heredity which insists that the descendants shall suffer by the faults and profit by the virtues of their ancestors comprises truths that are no longer disputed. They shine forth, visible to the eyes of all. The child of a drunkard will bear the burden of his father’s vice all his life long, from the day of his birth to that of his death, in body and in mind. ”

“ The law of heredity has long been suspected, and, in late years, has been, to a considerable extent, regarded as the demonstrated and universal order of nature. It is the law by which the offspring inherits the qualities and characteristics of its ancestors. ”

“ HEREDITY.—The transmission of bodily resemblance and of traits of character from parent to child is a broad and complicated subject, whose fundamental principles biologists are just beginning to grasp. The facts thus far established regarding heredity relate chiefly to plants and to the lower animals. There is no doubt whatever that the meager knowledge we possess of heredity in man will be amplified and will ultimately indicate on the one hand the marriages which are advisable and, on the other hand, those which are not. ”

“ The fact that we are human beings instead of animals, that we have our due proportion of organs and faculties, that we are not monstrosities or imbeciles, are all hereditary conditions. We see, then, that the law of heredity insures to us our full complement of organs and capabilities, as well as the more pronounced characteristics which we the more readily recognize as inheritances. The fact is that inheritance of good is so universal that we fail to think of it. ”

“ While it is true that too much importance cannot be placed upon the subject of heredity, the inheritance which we receive not only from our parents and grandparents but even from our great-grandparents, and while it is true that all that can be acquired in character and culture, both intellectual and physical, is transmitted from the parents to their children ”

“ Cases of heredity will never be, in the domain of physiology, any thing more than exceptions, as compared with the cases which make against heredity. But now, if these are only exceptions, by what right shall any man set up heredity as the general law of the development of intellectual activity, or affirm that heredity is here the law, non-heredity the exception? Ribot accumulates the subtlest of arguments to strengthen this singular proposition, but he is wasting his time, wasting his talent. ”

“ Again, those who dwell on the objection from heredity forget that they are accentuating similari74ties and overlooking divergencies. For while investigations on the line of heredity have recorded many transmitted traits, they have not done so in respect to divergencies from heredity vastly greater in number. Every mother knows that the children of a family are as different in character as the fingers on one hand—they are all from the same parents, but all vary in character and capacity. ”

“ This wonderful force which causes the likeness of the child to its parents and to their parents we call heredity. Heredity causes the plants as well as animals to be like their parents. If we trace the workings of heredity in our own individual case, we will probably find that we are molded like our ancestors not only in physical characteristics but in mental qualities as well. The ability to play the piano or to paint is probably as much a case of inheritance as the color of our eyes or the shape of our nose. ”

“ As Nature takes the human embryo through repetitions of its discarded forms—fish, reptile, mammal, and vertebrate—before bringing it to birth, so whoever introduced, let us say, the word heredity in the nineteenth century went through the instinctive process of deriving from the Latin ‘hereditare’ an imaginary French word, ‘heredité’, and converting the latter into heredity. ”

“ Let us now turn to another phase of our subject and consider the biological methods of the description and measurement of heredity, as a preliminary to our next chapter in which we shall discuss the bearings of the facts of human heredity upon the possibility of the formation of a permanently improved human breed.
The fact of heredity is one of the most familiar and patent things about organisms. "Do men gather grapes of thorns or figs of thistles?" For we may define heredity as the fact of general resemblance between parent and offspring. ”

“ All are but recognitions of the same common fact that offspring exhibit various characteristics similar to those of their progenitors.
Blood Heritage.—To this phenomenon of resemblance in successive generations based on ancestry the term heredity is applied. In man, for instance, there is a marked tendency toward the reappearance in offspring of structures, habits, features, and even personal mannerisms, minute physical defects, and intimate mental peculiarities like those possessed by their parents or more remote forebears. ”

“ Heredity is "descent," or "breed." Heredity, as the word is here used, means those qualities which are handed down from one generation to the next. It means those qualities which a new generation inherits from the generation from whom it descends.
It means all that "is bred in the bone." If a man inherits a Grecian nose, a violent temper, well-knit muscles, a love of excitement, or a good ear for music, from his father or mother, that quality or feature is part of his heredity. ”

“ Yes, I am aware that by most of your thinkers the law of heredity is thought to be accountable for the great diversity of forms, features and mental characteristics of families, and to a degree they are correct, but only to a degree. ”

“ It is my purpose to review briefly some of the problems which the study of heredity presents, and some of the results obtained from their consideration.
"Like father like son" is a homely proverb which shows how general the recognition is that children resemble their parents. Resemblances to grandparents or ancestors even more remote are also of frequent occurrence, and it is convenient to use the term heredity as including all such resemblances, whether to near or to remote ancestors. The phenomenon of heredity is of course not restricted to human society. ”

“ What one receives at birth constitutes his heredity.—This consists of a normal or defective{513} physical constitution, the natural bent of mind and its rudimentary possibilities and the innate tendencies toward good or evil. The physical, mental and moral influences one receives after birth constitute his environment. Ideal environment tends to direct, develop and to mature the results of good heredity and to correct the results of bad heredity. ”

“ The human mind has been soaked in heredity as long back as we can trace its thought. Hereditary peers, hereditary monarchs, hereditary castes and trades and classes were the best known of social institutions, and in some cases of public nuisances. Pedigree men counted pedigree dogs and pedigree horses among their most cherished possessions. Far from being unconscious of heredity, or sceptical, men were insanely credulous about it: they not only believed in the transmission of qualities and habits from generation to generation, but expected the son to begin mentally where the father left off. ”

“ If we consider only the phenomena of heredity, which are nowhere so completely and clearly put together as in Darwin’s works, we find that he presents so-called laws of heredity, that is, he has noted the most frequent phenomena of heredity, and thence deduced a law. If the phenomena in the conveyance of a disease to one’s descendants are to be called heredity, they must correspond with the rest of the phenomena of heredity. ”

“ There are so many false and, indeed, from a scientific standpoint, utterly groundless notions with regard to heredity which, as a result of the popularization of science, have become widely diffused, that notions about inheritance are a most copious source of dreads and discouragement and even produce inhibition of resistive vitality against disease on the part of many patients. ”

“ What, let me ask, are the principal phenomena of heredity? There must be physical continuity between parent, or parents, and offspring, so that the offspring is, as Erasmus Darwin well said, a kind of elongation of the life of the parent. ”

“ The social discords that spring up among a people like those that so often divide the families of degenerates, taken together, constitute a manifestation of the dissolution of heredity; their source is in a biological fact.
The facts that authorize us to regard morbid heredity or degeneration in general as the consequence of disorders of nutrition during the developmental period of evolution permit us to comprehend the exceptions to the laws of heredity, and consequently to conceive the possibility of securing means of favoring these exceptions and of contending against degeneration. ”

“ I would call attention at once to the special phenomenon which explains the problem of her destiny: I mean by this her heredity, or rather the radical and violent contrast of her maternal and paternal heredity. ”

“ To sum up, we have reason to believe not only that one's mental character is due largely to heredity, but that the details of it may be equally due to heredity, in the sense that for any particular trait or complex in the child there is likely to be found a similar trait or complex in the ancestry. Such a conclusion should not be pushed to the point of assuming inheritance of all sorts of dispositions that might be due to early training; on the other hand, a survey of the whole field would probably justify us in concluding that any given trait is more likely than not to be inherited. ”

“ Is heredity akin to the habit-memory which is preserved in our brains and bodies? There are men who tell us that the best conception of heredity they can form is something of this kind. They tell us that they think of individual lives as inscribing on germ-cells, by constant repetition, effects of what they have done. They tell us that the habit-memory of ancestral and thus communicated experience enables the baby to pump food into its mouth with that accurate adjustment of muscular means to exterior conditions and the principles of hydrostatics which it always shows. ”

“ Every mother, if not her children, has often heard the word “heredity” mentioned. The offspring is part and parcel of the parents, and inherits, somewhat changed or modified perhaps, not only their good qualities, their strength of body, brain, and constitution, but their diseases also, if they have any. ”

“ It may be remarked, in a general way, that the subject of heredity is one of profoundest significance in its relation to society. Through its influences the peculiarities and characteristics of families and nations are largely developed and perpetuated. ”

“ If environment, education, imitation and other causes do not account for the phenomena, then heredity must. Heredity thus becomes a convenient name by which to denominate the insolvable. Sometimes the denomination is correct and sometimes incorrect, and very often, even when correct, it conveys a wrong impression. The impression being that the influence of heredity is altogether irresistible and also ineradicable. ”

“ The fundamental question connected with the theory of heredity is: How can a single cell of the body contain within itself all the hereditary tendencies of the hypothesis of the continuity of the germ-plasm gives an identical starting-point to each successive generation, and thus explains how it is that an identical product arises from all of them. In other words, the hypothesis explains heredity as part of the underlying problems of assimilation and of the causes which act directly during ontogeny. ”

“ Heredity, instead of being resemblance, was an effort toward resemblance thwarted by circumstances and environment. And he had arrived at what he called the hypothesis of the abortion of cells. Life is only motion, and heredity being a communicated motion, it happened that the cells in their multiplication from one another jostled one another, pressed one another, made room for themselves, putting forth, each one, the hereditary effort ”

“ Heredity provides the tenement and also imposes those limitations of capacity of brain or body which are often a punishment and sometimes a help, but it does not affect the real Ego. The transmission of traits is a physical matter, and nothing more than the coming out into a nation of the consequences of the prior lives of all Egos who are to be in that race. The limitations imposed on the Ego by any family heredity are exact consequences of that Ego’s prior lives. ”

“ To fight against the sins and penalties of one's grandfather is a forlorn task that quickly discourages. To overcome diseases of environment, of shop and street, of house and school, seems, on the contrary, an easy task. Heredity bugaboos dishearten, enervate, encourage excesses and neglect. Heredity truths stimulate remedial and preventive measures. ”