The task, as this chapter was intended to show, is a complex one, yet we see no insuperable obstacles to it. Eugenics may not become a part of the Christian religion, as a whole, until scientific education is much more widespread than at present, but it is not too soon to make a start, by identifying the interests of the two wherever such identification is justified and profitable.
We have endeavored to point out that as a race rises, and instinct becomes less important in guiding the conduct of its members, religion has often put a restraint on reason, guiding the individual in racially profitable paths. What is to happen when religion gives way? Unbridled selfishness too often takes the reins, and the interests of the species are disregarded. Religion, therefore, appears to be a necessity for the perpetuation of any race. It is essential to racial welfare that the national religion should be of such a character as to appeal to the emotions effectively and yet conciliate the reason. We believe that the religion of the future is likely to acquire this character, in proportion as it adheres to eugenics. There is no room in the civilized world now for a dysgenic religion. Science will progress. The idea of evolution will be more firmly grasped. Religion itself evolves, and any religion which does not embrace eugenics will embrace death.
CHAPTER XX
EUGENICS AND EUTHENICS
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:
| Number of fraternities | Number of children per fraternity | Total number of children in group |
|---|---|---|
| 1 | 2 | 2 |
| 11 | 3 | 33 |
| 8 | 4 | 32 |
| 17 | 5 | 85 |
| 13 | 6 | 78 |
| 14 | 7 | 98 |
| 9 | 8 | 72 |
| 11 | 9 | 99 |
| 10 | 10 | 100 |
| 3 | 11 | 33 |
| 2 | 12 | 24 |
| 1 | 13 | 13 |
| — | — | |
| 100 | 669 | |
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.