1. That it results in inferior offspring. This objection is not well supported except possibly in the most extreme cases. Physically, there is evidence that the younger parents on the whole bear the sounder children.
2. That a postponement of marriage provides the opportunity for better s.e.xual selection. This is a valid ground for discouraging the marriage of minors.
3. The better educated cla.s.ses are obliged to marry late, because a man usually can not marry until he has finished his education and established himself in business. A fair amount of restriction as to age at marriage will therefore not affect these cla.s.ses, but may affect the uneducated cla.s.ses. In so far as lack of education is correlated with eugenic inferiority, some restriction of this sort is desirable, because it will keep inferiors from reproducing too rapidly, as compared with the superior elements of the population.
While the widespread rule that men should not marry under 21 and women under 18 has some justification, then, an ideal law would permit exceptions where there was adequate income and good mating.
Laws to prohibit or restrict consanguineous marriages fall within the scope of this chapter, in so far as they are not based on dogma alone, since their aim is popularly supposed to be to prevent marriages that will result in undesirable offspring. Examining the laws of all the United States, C. B. Davenport[91] found the following cla.s.ses excluded from marriage:
1. Sibs (i.e., full brothers and sisters) in all states, and half sibs in most states.
2. Parent and child in all states, and parent and grandchild in all states except Pennsylvania.
3. Child and parent"s sibs (i.e., niece and uncle, nephew and aunt).
Prohibited in all but four states.
4. First cousins. Marriages of this type are prohibited in over a third of the states, and tacitly or specifically permitted in the others.
5. Other blood relatives are occasionally prohibited from marrying.
Thus, second cousins in Oklahoma and a child and his or her parent"s half sibs in Alabama, Minnesota, New Jersey, Texas, and other states.
In the closest of blood-relationships the well-nigh universal restrictions should be retained. But when marriage between cousins--the commonest form of consanguineous marriage--is examined, it is found to result frequently well, sometimes ill. There is a widespread belief that such marriages are dangerous, and in support of this idea, one is referred to the histories of various isolated communities where consanguineous marriage is alleged to have led to "an appalling amount of defect and degeneracy." Without questioning the facts, one may question the interpretation of the facts, and it seems to us that a wrong interpretation of these stories is partly responsible for the widespread condemnation of cousin marriage at the present time.
The Bahama Islands furnish one of the stock examples. Clement A. Penrose writes[92] of them:
"In some of the white colonies where black blood has been excluded, and where, owing to their isolated positions, frequent intermarriage has taken place, as for instance at Spanish Wells, and Hopetown, much degeneracy is present, manifested by many abnormalities of mind and body.... I am strongly of the opinion that the deplorable state of degeneracy which we observed at Hopetown has been in a great measure, if not entirely, brought about by too close intermarrying of the inhabitants."
To demonstrate his point, he took the pains to compile a family tree of the most degenerate strains at Hopetown. There are fifty-five marriages represented, and the chart is overlaid with twenty-three red lines, each of which is said to represent an intermarriage. This looks like a good deal of consanguineous mating; but to test the matter a little farther the fraternity at the bottom of the chart,--eight children, of whom five were idiots,--was traced. In the second generation it ran to another island, and when the data gave out, at the fourth generation, there was not a single case of consanguineous marriage involved.
Another fraternity was then picked out consisting of two men, both idiots and congenitally blind, and a woman who had married and given birth to ten normal children. In the fourth generation this pedigree, which was far from complete, went out of the islands; so far as the data showed there was not a single case of consanguineous marriage. There was one case where a name was repeated, but the author had failed to mark this as a case of intermarriage, if it really was such. It is difficult to share the conviction of Dr. Penrose, that the two pedigrees investigated, offer an example of the nefarious workings of intermarriage.
Finally a fraternity was traced to which the author had called particular attention because three of its eleven members were born blind. The defect was described as "optic atrophy a.s.sociated with a pigmentary retinitis and choryditis" and "this condition," Dr. Penrose averred, "is one stated by the authorities to be due to the effects of consanguineous marriage."
Fortunately, the pedigree was fairly full and several lines of it could be carried through the sixth generation. There was, indeed, a considerable amount of consanguineous marriage involved. When the amount of inbreeding represented by these blind boys was measured, it proved to be almost identical with the amount represented by the present Kaiser of Germany.[93]
We are unable to see in such a history as that of Hopetown, Bahama Islands, any evidence that consanguineous marriage necessarily results in degeneracy. Dr. Penrose himself points to a potent factor when he says of his chart in another connection: "It will be noticed that only a few of the descendants of Widow Malone [the first settler at Hopetown]
are indicated as having married. By this it is not meant that the others did not marry; many of them did, but they moved away and settled elsewhere, and in no way affected the future history of the settlement of Hopetown."
By moving away, it appears to us, they did very decidedly affect the future history of Hopetown. Who are the emigrants? Might they not have been the more enterprising and intelligent, the physically and mentally superior of the population, who rebelled at the limited opportunities of their little village, and went to seek a fortune in some broader field?
Did not the best go in general; the misfits, the defectives, stay behind to propagate? Emigration in such a case would have the same effect as war; it would drain off the best stock and leave the weaklings to stay home and propagate their kind. Under such conditions, defectives would be bound to multiply, regardless of whether or not the marriages are consanguineous.
"It will be seen at a glance," Dr. Penrose writes, "that early in the history of the Malone family these indications of degeneracy were absent; but they began in the fourth generation and rapidly increased afterward until they culminated by the presence of five idiots in one family. The original stock was apparently excellent, but the present state of the descendants is deplorable."
Now three generations of emigration from a little community, which even to-day has only 1,000 inhabitants, would naturally make quite a difference in the average eugenic quality of the population. In almost any population, a few defectives are constantly being produced. Take out the better individuals, and leave these defectives to multiply, and the amount of degeneracy in the population will increase, regardless of whether the defectives are marrying their cousins, or unrelated persons.
The family of five idiots, cited by Dr. Penrose, is an excellent ill.u.s.tration, for it is not the result of consanguineous marriage--at least, not in a close enough degree to have appeared on the chart. It is doubtless a mating of like with like; and biologically, consanguineous marriage is nothing more.
Honesty demands, therefore, that consanguineous marriage be not credited with results for which the consanguineous element is in no wise responsible. The prevailing habit of picking out a community or a strain where consanguineous marriage and defects are a.s.sociated and loudly declaring the one to be the cause of the other, is evidence of the lack of scientific thought that is all too common.
Most of the studies of these isolated communities where intermarriage has taken place, ill.u.s.trate the same point. C. B. Davenport, for example, quotes[94] an anonymous correspondent from the island of Bermuda, which "shows the usual consequence of island life." He writes: "In some of the parishes (Somerset and Paget chiefly) there has been much intermarriage, not only with cousins but with double first cousins in several cases.
Intermarriage has chiefly caused weakness of character leading to drink, not lack of brains or a certain amount of physical strength, but a very inert and lazy disposition."
It is difficult to believe that anyone who has lived in the tropics could have written this except as a practical joke. Those who have resided in the warmer parts of the world know, by observation if not by experience, that a "weakness of character leading to drink" and "an inert and lazy disposition" are by no means the prerogatives of the inbred.
If one is going to credit consanguineous marriage with these evil results, what can one say when evil results fail to follow?
What about Smith"s Island, off the coast of Maryland, where all the inhabitants are said to be interrelated, and where a physician who lived in the community for three years failed to find among the 700 persons a single case of idiocy, insanity, epilepsy or congenital deafness?
What about the community of Batz, on the coast of France, where Voisin found five marriages of first cousins and thirty-one of second cousins, without a single case of mental defect, congenital deafness, albinism, retinitis pigmentosa or malformation? The population was 3,000, all of whom were said to be interrelated.
What about Cape Cod, whose natives are known throughout New England for their ability? "At a recent visit to the Congregational Sunday-School,"
says a student, "I noticed all officers, many teachers, organist, ex-superintendent, and pastor"s wife all Dyers. A lady at Truro united in herself four quarters Dyer, father, mother and both grandmothers Dyers."
And finally, what about the experience of livestock breeders? Not only has strict brother and sister mating--the closest inbreeding possible--been carried on experimentally for twenty or twenty-five generations without bad results; but the history of practically every fine breed shows that inbreeding is largely responsible for its excellence.
The Ptolemies, who ruled Egypt for several centuries, wanted to keep the throne in the family, and hence practiced a system of intermating which has long been the cla.s.sical evidence that consanguineous marriage is not necessarily followed by immediate evil effects. The following fragment of the genealogy of Cleopatra VII (mistress of Julius Caesar and Marc Antony) is condensed from Weigall"s _Life and Times of Cleopatra_ (1914) and
Ptolemy I | | Ptolemy II | | Ptolemy III m. Berenice II, his half-cousin.
| | Ptolemy IV m. Arsinoe III, his full sister.
| | Ptolemy V.
| | Ptolemy VII m. Cleopatra II, his full sister.
| | Cleopatra III m. Ptolemy IX (brother of VII), her uncle.
| | Ptolemy X. m. Cleopatra IV, his full sister.
| -----| | Berenice II m. Ptolemy XI (brother of X), her uncle.
| | | | | Ptolemy XII, d. without issue, succeeded by his uncle.
| | | | ---Ptolemy XIII.
| | Cleopatra VII.
shows an amount of continued inbreeding that has never been surpa.s.sed in recorded history, and yet did not produce any striking evil results. The ruler"s consort is named, only when the two were related. The consanguineous marriages shown in this line of descent are by no means the only ones of the kind that took place in the family, many like them being found in collateral lines.
It is certain that consanguineous marriage, being the mating of like with like, intensifies the inheritance of the offspring, which gets a "double dose" of any trait which both parents have in common. If the traits are good, it will be an advantage to the offspring to have a double dose of them; if the traits are bad, it will be a disadvantage.
The marriage of superior kin should produce children better than the parents; the marriage of inferior kin should produce children even worse than their parents.
In pa.s.sing judgment on a proposed marriage, therefore, the vital question is not, "Are they related by blood?" but "Are they carriers of desirable traits?"
The nature of the traits can be told only by a study of the ancestry. Of course, characters may be latent or recessive, but this is also the case in the population at large, and the chance of unpleasant results is so small, when no instance can be found in the ancestry, that it can be disregarded. If the same congenital defect or undesirable trait does not appear in the three previous generations of two cousins, including collaterals, the individuals need not be discouraged from marrying if they want to.
Laws which forbid cousins to marry are, then, on an unsound biological basis. As Dr. Davenport remarks, "The marriage of Charles Darwin and Emma Wedgewood would have been illegal and void, and their children p.r.o.nounced illegitimate in Illinois, Indiana, Iowa, Kansas, Missouri, Nebraska, New Hampshire, Oklahoma, Oregon, Pennsylvania, South Dakota, Utah, Washington, Wyoming, and other states." The vitality and great capacity of their seven children are well known. A law which would have prevented such a marriage is certainly not eugenic.
We conclude, then, that laws forbidding cousin marriages are not desirable. Since it would be well to make an effort to increase the opportunities for further play of s.e.xual selection, the lack of which is sometimes responsible for cousin marriages, consanguineous marriage is by no means to be indiscriminately indorsed. Still, if there are cases where it is eugenically injurious, there are also cases where its results are eugenically highly beneficial, as in families with no serious defects and with outstanding ability.
The laws prohibiting marriage between persons having no blood relationship but connected by marriage should all be repealed. The best-known English instance, which was eugenically very objectionable,--the prohibition of marriage between a man and his deceased wife"s sister,--has fortunately been extirpated, but laws still exist, in some communities, prohibiting marriage between a man and his stepchild or stepparent, between a woman and her deceased husband"s brother, and between the second husband or wife of a deceased aunt or uncle and the wife or husband of a deceased nephew or niece, etc.
The only other problem of restrictive eugenics which it seems necessary to consider is that offered by miscegenation. This will be considered in Chapters XIV and XV.
To sum up: we believe that there are urgent reasons for and no objections to preventing the reproduction of a number of persons in the United States, many of whom have already been recognized by society as being so anti-social or inferior as to need inst.i.tutional care. Such restriction can best be enforced by effective segregation of the s.e.xes, although there are cases where individuals might well be released and allowed full freedom, either "on parole," so to speak, or after having undergone a surgical operation which would prevent their reproduction.
Laws providing for sterilization, such as a dozen states now possess, are not framed with a knowledge of the needs of the case; but a properly drafted sterilization law to provide for cases not better treated by segregation is desirable. Segregation should be considered the main method.
It is practicable to place only minor restrictions on marriage, with a eugenic goal in view. A good banns law, however, could meet no objections and would yield valuable results. Limited age restrictions are proper.