Emphasis has been given, in several of the foregoing chapters, to the desirability of inheriting a good constitution and a high degree of vigor and disease-resistance. It has been asserted that no measures of hygiene and sanitation can take the place of such inheritance. It is now desirable to ascertain the limits within which good inheritance is effective, and this may be conveniently done by a study of the lives of a group of people who inherited exceptionally strong physical constitutions.

The people referred to are taken from a collection of histories of long life made by the Genealogical Record Office of Washington.[189] One hundred individuals were picked out at random, each of whom had died at the age of 90 or more, and with the record of each individual were placed those of all his brothers and sisters. Any family was rejected in which there was a record of wholly accidental death (e.g., families of which a member had been killed in the Civil War). The 100 families, or more correctly fraternities or sibships, were classified by the number of children per fraternity, as follows:

The average at death of these 669 persons was 64.7 years. The child mortality (first 4 years of life) was 7.5% of the total mortality, 69 families showing no deaths of that kind. The group is as a whole, therefore, long-lived.

The problem was to measure the resemblance between brothers and sisters in respect of longevity,—to find whether knowledge of the age at which one died would justify a prediction as to the age at death of the others,—or technically, it was to measure the fraternal correlation of longevity. A zero coefficient here would show that there is no association; that from the age at which one dies, nothing whatever can be predicted as to the age at which the others will die. Since it is known that heredity is a large factor in longevity, such a finding would mean that all deaths were due to some accident which made the inheritance of no account.

In an ordinary population it has been found that the age at death of brothers and sisters furnishes a coefficient of correlation of the order of .3, which shows that heredity does determine the age at which one shall die to considerable extent, but not absolutely.[190]

The index of correlation[191] between the lengths of life within the fraternity in these 100 selected families, furnished a coefficient of-.0163±.0672, practically zero. In other words, if the age is known at which a member of one of these families died, whether it be one month or 100 years, nothing whatever can be predicted about the age at which his brothers and sisters died.

Remembering that longevity is in general inherited, and that it is found in the families of all the people of this study (since one in each fraternity lived to be 90 or over) how is one to interpret this zero coefficient? Evidently it means that although these people had inherited a high degree of longevity, their deaths were brought about by causes which prevented the heredity from getting full expression. As far as hereditary potentialities are concerned, it can be said that all their deaths were due to accident, using that word in a broad sense to include all non-selective deaths by disease. If they had all been able to get the full benefit of their heredity, it would appear that each of these persons might have lived to 90 or more, as did the one in each family who was recorded by the Genealogical Record Office. Genetically, these other deaths may be spoken of as premature.

In an ordinary population, the age of death is determined to the extent of probably 50% by heredity. In this selected long-lived population, heredity appears not to be responsible in any measurable degree whatsoever for the differences in age at death.

The result may be expressed in another, and perhaps more striking, way. Of the 669 individuals studied, a hundred—namely, one child in each family—lived beyond 90; and there were a few others who did. But some 550 of the group, though they had inherited the potentiality of reaching the average age of 90, actually died somewhere around 60; they failed by at least one-third to live up to the promise of their inheritance. If we were to generalize from this single case, we would have to say that five-sixths of the population does not make the most of its physical inheritance.

This is certainly a fact that discourages fatalistic optimism. The man who tells himself that, because of his magnificent inherited constitution, he can safely take any risk, is pretty sure to take too many risks and meet with a non-selective—i.e., genetically, a premature—death, when he might in the nature of things have lived almost a generation longer.

It should be remarked that most of the members of this group seem to have lived in a hard environment. They appear to belong predominantly to the lower strata of society; many of them are immigrants and only a very few of them, to judge by a cursory inspection of the records, possessed more than moderate means. This necessitated a frugal and industrious life which in many ways was doubtless favorable to longevity but which may often have led to overexposure, overwork, lack of proper medical treatment, or other causes of a non-selective death. We would not push the conclusion too far, but we can not doubt that this investigation shows the folly of ignoring the environment,—shows that the best inherited constitution must have a fair chance. And what has here been found for a physical character, would probably hold good in even greater degree for a mental character. All that man inherits is the capacity to develop along a certain line under the influence of proper stimuli,—food and exercise. The object of eugenics is to see that the inherent capacity is there. Given that, the educational system is next needed to furnish the stimuli. The consistent eugenist is therefore an ardent euthenist. He not only works for a better human stock but, because he does not want to see his efforts wasted, he always works to provide the best possible environment for this better stock.

In so far, then, as euthenics is actually providing man with more favorable surroundings,—not with ostensibly more favorable surroundings which, in reality, are unfavorable—there can be no antagonism between it and eugenics. Eugenics is, in fact, a prerequisite of euthenics, for it is only the capable and altruistic man who can contribute to social progress; and such a man can only be produced through eugenics.

Eugenic fatalism, a blind faith in the omnipotence of heredity regardless of the surroundings in which it is placed, has been shown by the study of long-lived families to be unjustified. It was found that even those who inherited exceptional longevity usually did not live as long as their inheritance gave them the right to expect. If they had had more euthenics, they should have lived longer.

But this illustration certainly gives no ground for a belief that euthenics is sufficient to prolong one's life beyond the inherited limit. A study of these long-lived families from another point of view will reveal that heredity is the primary factor and that good environment, euthenics, is the secondary one.

For this purpose we augment the 100 families of the preceding section by the addition of 240 more families like them, and we examine each family history to find how many of the children died before completing the fourth year of life. The data are summarized in the following table:

Child Mortality in Families of Long-lived Stock, Genealogical Record Office Data

The addition of the new families (which were not subjected to any different selection than the first 100) has brought down the child mortality rate. For the first 100, it was found to be 7.5%. If in the above table the number of child deaths, 119, be divided by the total number of children represented, 2,259, the child mortality rate for this population is found to be 5.27%, or 53 per thousand.

The smallness of this figure may be seen by comparison with the statistics of the registration area, U. S. Census of 1880, when the child mortality (0-4 years) was 400 per thousand, as calculated by Alexander Graham Bell. A mortality of 53 for the first four years of life is smaller than any district known in the United States, even to-day, can show for the first year of life alone. If any city could bring the deaths of babies during their first twelve months down to 53 per 1,000, it would think it had achieved the impossible; but here is a population in which 53 per 1,000 covers the deaths, not only of the fatal first 12 months, but of the following three years in addition.

Now this population with an unprecedentedly low rate of child mortality is not one which had had the benefit of any Baby Saving Campaign, nor even the knowledge of modern science. Its mothers were mostly poor, many of them ignorant; they lived frequently under conditions of hardship; they were peasants and pioneers. Their babies grew up without doctors, without pasteurized milk, without ice, without many sanitary precautions, usually on rough food. But they had one advantage which no amount of applied science can give after birth—namely, good heredity. They had inherited exceptionally good constitutions.

It is not by accident that inherited longevity in a family is associated with low mortality of its children. The connection between the two facts was first discovered by Mary Beeton and Karl Pearson in their pioneer work on the inheritance of duration of life. They found that high infant mortality was associated with early death of parents, while the offspring of long-lived parents showed few deaths in childhood. The correlation of the two facts was quite regular, as will be evident from a glance at the following tables prepared by A. Ploetz:

Length of Life of Mothers and Child-mortality of Their Daughters. English Quaker Families, Data of Beeton and Pearson, Arranged by Ploetz

Length of Life of Fathers and Child-mortality of Their Daughters

To save space, we do not show the relation between parent and son; it is similar to that of parent and daughter which is shown in the preceding tables. In making comparison with the 340 families from the Genealogical Record Office, above studied, it must be noted that Dr. Ploetz' tables include one year longer in the period of child mortality, being computed for the first five years of life instead of the first four. His percentages would therefore be somewhat lower if computed on the basis used in the American work.

These various data demonstrate the existence of a considerable correlation between short life (brachybioty, Karl Pearson calls it) in parent and short life in offspring. Not only is the tendency to live long inherited, but the tendency not to live long is likewise inherited.

But perhaps the reader may think they show nothing of the sort. He may fancy that the early death of a parent left the child without sufficient care, and that neglect, poverty, or some other factor of euthenics brought about the child's death. Perhaps it lacked a mother's loving attention, or perhaps the father's death removed the wage-earner of the family and the child thenceforth lacked the necessities of life.

Dr. Ploetz has pointed out[192] that this objection is not valid, because the influence of the parent's death is seen to hold good even to the point where the child was too old to require any assistance. If the facts applied only to cases of early death, the supposed objection might be weighty, but the correlation exists from one end of the age-scale to the other. It is not credible that a child is going to be deprived of any necessary maternal care when its mother dies at the age of 69; the child herself was probably married long before the death of the mother. Nor is it credible that the death of the father takes bread from the child's mouth, leaving it to starve to death in the absence of a pension for widowed mothers, if the father died at 83, when the "child" herself was getting to be an old woman. The early death of a parent may occasionally bring about the child's death for a reason wholly unconnected with heredity, but the facts just pointed out show that such cases are exceptional. The steady association of the child death-rate and parent death-rate at all ages demonstrates that heredity is a common cause.

But the reader may suspect another fallacy. The cause of this association is really environmental, he may think, and the same poverty or squalor which causes the child to die early may cause the parent to die early. They may both be of healthy, long-lived stock, but forced to live in a pestiferous slum which cuts both of them off prematurely and thereby creates a spurious correlation in the statistics.

We can dispose of this objection most effectively by bringing in new evidence. It will probably be admitted that in the royal families of Europe, the environment is as good as knowledge and wealth can make it. No child dies for lack of plenty of food and the best medical care, even if his father or mother died young. And the members of this caste are not exposed to any such unsanitary conditions, or such economic pressure as could possibly cause both parent and child to die prematurely. If the association between longevity of parent and child mortality holds for the royal families of Europe and their princely relatives, it can hardly be regarded as anything but the effect of heredity,—of the inheritance of a certain type of constitution.

Dr. Ploetz studied the deaths of 3,210 children in European royalty, from this viewpoint. The following table shows the relation between father and child:

Length of Life of Fathers and Child-mortality of Their Children in Royal and Princely Families, Ploetz' Data

Allowing for the smallness of some of the groups, it is evident that the amount of correlation is about the same here as among the English Quakers of the Beeton-Pearson investigation, whose mortality was shown in the two preceding tables. In the healthiest group from the royal families—the cases in which the father lived to old age—the amount of child mortality is about the same as that of the Hyde family in America, which Alexander Graham Bell has studied—namely, somewhere around 250 per 1,000. One may infer that the royal families are rather below par in soundness of constitution.[193]

All these studies agree perfectly in showing that the amount of child mortality is determined primarily by the physical constitution of the parents, as measured by their longevity. In the light of these facts, the nature of the extraordinarily low child mortality shown in the 340 families from the Genealogical Record Office, with which we began the study of this point, can hardly be misunderstood. These families have the best inherited constitution possible and the other studies cited would make us certain of finding a low child mortality among them, even if we had not directly investigated the facts.

If the interpretation which we have given is correct, the conclusion is inevitable that child mortality is primarily a problem of eugenics, and that all other factors are secondary. There is found to be no warrant for the statement so often repeated in one form or another, that "the fundamental cause of the excessive rate of infant mortality in industrial communities is poverty, inadequate incomes, and low standards of living."[194] Royalty and its princely relatives are not characterized by a low standard of living, and yet the child mortality among them is very high—somewhere around 400 per 1,000, in cases where a parent died young. If poverty is responsible in the one case, it must be in the other—which is absurd. Or else the logical absurdity is involved of inventing one cause to explain an effect to-day and a wholly different cause to explain the same effect to-morrow. This is unjustifiable in any case, and it is particularly so when the single cause that explains both cases is so evident. If weak heredity causes high mortality in the royal families, why, similarly, can not weak heredity cause high infant mortality in the industrial communities? We believe it does account for much of it, and that the inadequate income and low standard of living are largely the consequences of inferior heredity, mental as well as physical. The parents in the Genealogical Record Office files had, many of them, inadequate incomes and low standards of living under frontier conditions, but their children grew up while those of the royal families were dying in spite of every attention that wealth could command and science could furnish.

If the infant mortality problem is to be solved on the basis of knowledge and reason, it must be recognized that sanitation and hygiene can not take the place of eugenics any more than eugenics can dispense with sanitation and hygiene. It must be recognized that the death-rate in childhood is largely selective, and that the most effective way to cut it down is to endow the children with better constitutions. This can not be done solely by any euthenic campaign; it can not be done by swatting the fly, abolishing the midwife, sterilizing the milk, nor by any of the other panaceas sometimes proposed.

But, it may be objected, this discussion ignores the actual facts. Statistics show that infant mortality campaigns have consistently produced reductions in the death-rate. The figures for New York, which could be matched in dozens of other cities, show that the number of deaths per 1,000 births, in the first year of life, has steadily declined since a determined campaign to "Save the Babies" was started:

To one who can not see beyond the immediate consequences of an action, such figures as the above indeed give quite a different idea of the effects of an infant mortality campaign, than that which we have just tried to create. And it is a great misfortune that euthenics so often fails to look beyond the immediate effect, fails to see what may happen next year, or 10 years from now, or in the next generation.

We admit that it is possible to keep a lot of children alive who would otherwise have died in the first few months of life. It is being done, as the New York figures, and pages of others that could be cited, prove. The ultimate result is twofold:

1. Some of those who are doomed by heredity to a selective death, but are kept alive through the first year, die in the second or third or fourth year. They must die sooner or later; they have not inherited sufficient resistance to survive more than a limited time. If they are by a great effort carried through the first year, it is only to die in the next. This is a statement which we have nowhere observed in the propaganda of the infant mortality movement; and it is perhaps a disconcerting one. It can only be proved by refined statistical methods, but several independent determinations by the English biometricians leave no doubt as to the fact. This work of Karl Pearson, E. C. Snow, and Ethel M. Elderton, was cited in our chapter on natural selection; the reader will recall how they showed that nature is weeding out the weaklings, and in proportion to the stringency with which she weeds them out at the start, there are fewer weaklings left to die in succeeding years.

To put the facts in the form of a truism, part of the children born in any district in a given year are doomed by heredity to an early death; and if they die in one year they will not be alive to die in the succeeding year, and vice versa. Of course there are in addition infant deaths which are not selective and which if prevented would leave the infant with as good a chance as any to live.

In the light of these researches, we are forced to conclude that baby-saving campaigns accomplish less than is thought; that the supposed gain is to some extent temporary and illusory.

2. There is still another consequence. If the gain is by great exertions made more than temporary; if the baby who would otherwise have died in the first months is brought to adult life and reproduction, it means in many cases the dissemination of another strain of weak heredity, which natural selection would have cut off ruthlessly in the interests of race betterment. In so far, then, as the infant mortality movement is not futile it is, from a strict biological viewpoint, often detrimental to the future of the race.

Do we then discourage all attempts to save the babies? Do we leave them all to natural selection? Do we adopt the "better dead" gospel?

Unqualifiedly, no! The sacrifice of the finer human feelings, which would accompany any such course, would be a greater loss to the race than is the eugenic loss from the perpetuation of weak strains of heredity. The abolition of altruistic and humanitarian sentiment for the purpose of race betterment would ultimately defeat its own end by making race betterment impossible.

But race betterment will also be impossible unless a clear distinction is made between measures that really mean race betterment of a fundamental and permanent nature, and measures which do not.

We have chosen the Infant Mortality Movement for analysis in this chapter because it is an excellent example of the kind of social betterment which is taken for granted, by most of its proponents, to be a fundamental piece of race betterment; but which, as a fact, often means race impairment. No matter how abundant and urgent are the reasons for continuing to reduce infant mortality wherever possible, it is dangerous to close the eyes to the fact that the gain from it is of a kind that must be paid for in other ways; that to carry on the movement without adding eugenics to it will be a short-sighted policy, which increases the present happiness of the world at the cost of diminishing the happiness of posterity through the perpetuation of inferior strains.

While some euthenic measures are eugenically evils, even if necessary ones, it must not be inferred that all euthenic measures are dysgenic. Many of them, such as the economic and social changes we have suggested in earlier chapters, are an important part of eugenics. Every euthenic measure should be scrutinized from the evolutionary standpoint; if it is eugenic as well as euthenic, it should be whole-heartedly favored; if it is dysgenic but euthenic it should be condemned or adopted, according to whether or not the gain in all ways from its operation will exceed the damage.

In general, euthenics, when not accompanied by some form of selection (i. e., eugenics) ultimately defeats its own end. If it is accompanied by rational selection, it can usually be indorsed. Eugenics, on the other hand, is likewise inadequate unless accompanied by constant improvement in the surroundings; and its advocates must demand euthenics as an accompaniment of selection, in order that the opportunity for getting a fair selection may be as free as possible. If the euthenist likewise takes pains not to ignore the existence of the racial factor, then the two schools are standing on the same ground, and it is merely a matter of taste or opportunity, whether one emphasizes one side or the other. Each of the two factions, sometimes thought to be opposing, will be seen to be getting the same end result, namely, human progress.

Not only are the two schools working for the same end, but each must depend in still another way upon the other, in order to make headway. The eugenist can not see his measures put into effect except through changes in law and custom—i. e., euthenic changes. He must and does appeal to euthenics to secure action. The social reformer, on the other hand, can not see any improvements made in civilization except through the discoveries and inventions of some citizens who are inherently superior in ability. He in turn must depend on eugenics for every advance that is made.

It may make the situation clearer to state it in the customary terms of biological philosophy. Selection does not necessarily result in progressive evolution. It merely brings about the adaptation of a species or a group to a given environment. The tapeworm is the stock example. In human evolution, the nature of this environment will determine whether adaptation to it means progress or retrogression, whether it leaves a race happier and more productive, or the reverse. All racial progress, or eugenics, therefore, depends on the creation of a good environment, and the fitting of the race to that environment. Every improvement in the environment should bring about a corresponding biological adaptation. The two factors in evolution must go side by side, if the race is to progress in what the human mind considers the direction of advancement. In this sense, euthenics and eugenics bear the same relation to human progress as a man's two legs do to his locomotion.

Social workers in purely euthenic fields have frequently failed to remember this process of adaptation, in their efforts to change the environment. Eugenists, in centering their attention on adaptation, have sometimes paid too little attention to the kind of environment to which the race was being adapted. The present book holds that the second factor is just as important as the first, for racial progress; that one leg is just as important as the other, to a pedestrian. Its only conflict with euthenics appertains to such euthenic measures as impair the adaptability of the race to the better environment they are trying to make.

Some supposedly euthenic measures opposed by eugenics are not truly euthenic, as for instance the limitation of a superior family in order that all may get a college education. For these spurious euthenic measures, something truly euthenic should be substituted.

Measures which show a real conflict may be typified by the infant mortality movement. There can be no doubt but that sanitation and hygiene, prenatal care and intelligent treatment of mothers and babies, are truly euthenic and desirable. At the same time, as has been shown, these euthenic measures result in the survival of inferior children, who directly or through their posterity will be a drag on the race. Euthenic measures of this type should be accompanied by counterbalancing measures of a more eugenic character.

Barring these two types, euthenics forms a necessary concomitant of the eugenic program; and, as we have tried to emphasize, eugenics is likewise necessary to the complete success of every euthenic program. How foolish, then, is antagonism between the two forces! Both are working toward the same end of human betterment, and neither can succeed without the other. When either attempts to eliminate the other from its work, it ceases to advance toward its goal. In which camp one works is largely a matter of taste. If on a road there is a gradient to be leveled, it will be brought down most quickly by two parties of workmen, one cutting away at the top, the other filling in the bottom. For the two parties to indulge in mutual scorn and recrimination would be no more absurd than for eugenics and euthenics to be put in opposition to each other. The only reason they have been in opposition is because some of the workers did not clearly understand the nature of their work. With the dissemination of a knowledge of biology, this ground of antagonism will disappear.