510. Notion that inbreeding is harmful. This taboo and the reasons for it are a complete enigma unless the primitive people had observed the evils of close inbreeding. Inbreeding maintains the excellence of a breed at the expense of its vigor. Outbreeding (unless too far out) develops vigor at the expense of the characteristic traits. It is very probable, but not absolutely certain, that inbreeding is harmful. Any marriage between persons who have the same faults of inheritance causes the offspring to accumulate faults and to degenerate. Close kinship creates a probable danger that faults will be accumulated. This is a logical deduction. Embryology, at present, seems to teach that there is a combination and extrusion of germ units of such a kind that the physiological process conforms only in a measure to this logical deduction, and the historical-statistical verification of the harm of inbreeding remains very imperfect. It is possible that at first, and within limits, inbreeding is not harmful, but becomes such if repeated often. Is it possible that the lowest savages can have perceived this and built a policy on it? Morgan[1660] thinks that it is possible. Westermarck[1661] thinks it beyond the mental power of the lowest races. He thinks that, by natural selection, those groups which practiced inbreeding for any reason died out or were displaced by those who followed the other policy. He goes on to propose a theory that persons who grew up, or who now grow up, in intimacy develop an instinctive antipathy to sex relations with each other.[1662] While it is true that primitive savages do not observe and reflect, it is also true that, in their own blundering way, when their interests are sharply at stake, they do observe, and they change their ways accordingly. Therefore they appear to us at one time hopelessly brutish; at another time we are amazed at their ingenuity and their mental activity (myths, legends, proverbs, maxims). If the loss or pain is great enough, the savage man is capable of astounding cleverness to escape it. After animal breeding began men had ample opportunity to observe the effects of close inbreeding. There is more doubt now about the penalties of inbreeding than there is about the power of savage men to perceive them and try to escape them, if they exist.
511. Status-wife, work-wife, love-wife. In the primitive horde it appears that there was a prescribed wife for each man, or the classification was such that his choice was restricted to a very small number. The prescribed wife was a status-wife. She alone could hold the position of a true "wife." The man might also capture a woman abroad who would be a worker, or work-wife, and she might win the man, so that she became a love-wife. There would often be a comparison between the children of the status-wife and the children of a work-wife or love-wife, in which the latter would appear the more vigorous. If so, there would be a school in which the advantages of outbreeding would appear as a fact, although not explained.
512. Abomination of incest. The taboos in the mores contain prescriptions as to the allowable consanguinity of spouses. There is a great horror of violating them. This sentiment is met with amongst people who have scarcely any other notion of crime, or of right and wrong. The rules are enforced by death or banishment as penalties of violation. The notion of harm in inbreeding has spread all over the earth. It has come down to ourselves. In the form in which it was held by savage people it was mistaken to such a degree that they might, in spite of it, practice close inbreeding. Our study of the mores teaches us that there must have been, antecedent to this state of the mores in regard to this matter, a long development of interests, folkways, rites, and superstitions.[1663] It is believed, not without reason, that the horde life would tend to run into grooves in which the prescribed wife would be a close relative, in the final case a sister. Experience of this might produce the rules of prohibition. The captured wife was also a trophy, and the play of this fact on vanity would always tend to disintegrate the system of endogamy. There are many reasons why endogamy seems more primitive than exogamy, and it required force of interest, superstition, or vanity to carry a society over from the former to the latter. A calamity might come to reënforce the interest,[1664] but can hardly be postulated to explain a custom so widespread. All the ultimate causes of the law of incest, therefore, lie beyond our investigation. They are open only to conjecture and speculation. The case is very important, however, to show the operation of the mores on facts erroneously assumed, and their power to work out their effects, as an independent societal operation, without regard to error in the material to which they are applied.
513. Incest taboo strongest in the strongest groups. We shall see, in the cases to be presented, that incest has a wider definition and a stricter compulsion in great tribes, and in prosperity or wealth, than in small groups and poverty. The definiteness of this taboo, and the strictness with which it is enforced, seem to be correlative with the energy of the tribal discipline in general and the vigor of the collective life of the group. Wives can be got abroad, either by capture or contract, only by those who command respect for their power or who use power. On the other hand, endogamy is both cause and effect of weakness and proceeds with decline. Some cases will be given below in which incestuous marriages occur where the parties are unable to obtain any other wives. Neglect of the incest taboo is rather a symptom than a cause of group decline.
514. Incest in ethnography. Martius says of the tribes on the upper Amazon, in general, that incest in all grades is frequent amongst them. In the more southern regions the taboo is stricter and better observed. Amongst the former it is shameful for a man to marry his sister or his brother's daughter. The usages are the more strict the larger the tribe is. In small isolated groups it frequently happens that a man lives with his sister. He heard of two tribes, the Coërunas and the Uainumus, who observed little rule on the subject. They were dying out.[1665] "Not seldom an Indian is father and brother of his son."[1666] Effertz writes that, amongst the Indians of the Sierra Madre, Mexico, incest between father and daughter "is of daily occurrence," although incest between brother and sister is entirely unknown. The former unions are due to economic interest. The Indian tills small bits of land scattered in the hills. He cannot exist without a woman to grind corn for him. When he goes to a distant patch of land he takes his daughter with him. He has but one blanket and the nights are cold. If he has no daughter he must take another woman, but then he must share his crop with her.[1667]
515. The tribes of South Australia are "forbidden to have intercourse with mothers, sisters, and first or second cousins. This religious law is strictly carried out and adhered to under penalty of death." The most opprobrious epithet for an opponent in a quarrel is one which means a person who has sex intercourse with kin nearer than second cousins.[1668] Some Dyaks are indifferent to the conduct of their wives, and both sexes practice sex vice, but they insist on drowning any one who violates the taboo of incest.[1669] Other Dyaks (the Ot Danom) have no notion of incest. The former are on the coast, the latter inland. Hence it seems probable that the notion of incest came to the Dyaks from outside.[1670] The Khonds practice female infanticide, from a feeling that marriage in the same tribe is incest.[1671] Cucis are allowed to marry without regard to relationship of blood, except mother and son.[1672] The Veddahs think marriage with an older sister abominable, but marriage with a younger sister is prescribed as the best. Sometimes a father marries his daughter; in other subdivisions a first cousin (daughter of the father's sister or mother's brother) is the prescribed wife.[1673] Mantegazza reports that father and daughter, mother and son, are not rarely united amongst the Anamites and that Cambodian brothers and sisters marry.[1674] Amongst the Kalongs on Java sons live with mothers, and luck and prosperity are thought to be connected with such unions. Not long ago, on Minahasa in the Tonsawang district, the closest blood relatives united in marriage; also on Timorlaut. The Balinese had a usage that twins of different sex, in the highest castes, were united in marriage. They could have no notion of incest at all.[1675] The Bataks have a tradition that marriage between a man and his father's sister's daughter was formerly allowed, but that calamities occurred which forced a change of custom.[1676]
516. The people of Teita, in East Africa, who are very dirty and low, marry mothers and sisters because they cannot afford to buy wives. They have been in touch with whites for fifty years.[1677] The chiefs of the Niam Niam take their daughters to wife.[1678] The Sakalava, on Madagascar, allow brother and sister to marry, but before such a marriage the bride is sprinkled with consecrated water and prayers are recited for her happiness and fecundity, as if there were fears that the union was not pleasing to the higher powers, and as if there was especial fear that there might be no offspring. Such marriages are contracted by chiefs who cannot find other brides of due rank.[1679]
517. The Ossetes think a marriage with a mother's sister right, but marriage with a father's sister is severely punished. They have the strictest father family. Marriage with a father's relative to the remotest cousinship is forbidden, but consanguinity through the mother they do not notice at all.[1680] The Ostiaks also have strict father family, and allow marriage with any relative on the female side, but with none on the male side. It is an especially fortunate marriage to take two sisters together.[1681]
518. Amongst the Tinneh, men sometimes marry their mothers, sisters, or daughters, but this is not approved by public opinion.[1682] As the Yakuts had no word for uterine brother and sister but only for tribal brother and sister, the statements about the taboo lack precision, but they care nothing for incest, and it occurs. They laugh at the Russian horror of it. They formerly had endogamy, and it is stated that brothers and sisters married. Now they have exogamy between subdivisions of the nation, but a girl's brothers never let her depart as a virgin, lest she take away their luck.[1683] A Hudson Bay Eskimo took his mother to wife, but public opinion forced him to discard her.[1684] Marriages of brothers and sisters appear to have been allowed formerly amongst the Mordvin, in central Russia. A case is mentioned of a girl who was sent from home for a time, and on her return given to her brother as his wife.[1685] Langsdorff[1686] reported of the Aleuts on the island of Kodiak, at the beginning of the nineteenth century, that parents and children, brothers and sisters, cohabited there.
519. Incest in civilized states. The ancient kings of Teneriffe, if they could not find mates of equal rank, married their sisters to prevent the admixture of plebeian blood.[1687] In the Egyptian mythology Isis and Osiris were sister and brother as well as wife and husband. The kings of ancient Egypt married their sisters and daughters. The doctrine of royal essence was very exaggerated, and was applied with quantitative exactitude. A princess could not be allowed to transmit any of it away from the possessor of the throne. There is said to be evidence that Ramses II married two of his own daughters and that Psammetik I married his daughter. Artaxerxes married two of his daughters.[1688] The Ptolemies adopted this practice. The family married in and in for generations, especially brothers and sisters, although sometimes of the half-blood. "Indicating the Ptolemies by numbers according to the order of their succession, II married his niece and afterwards his sister; IV his sister; VI and VII were brothers and they consecutively married the same sister; VII also subsequently married his niece; VIII married two of his own sisters consecutively; XII and XIII were brothers and consecutively married their sister, the famous Cleopatra." "The line of descent was untouched by these intermarriages, except in the two cases of III and VIII." The close intermarriages were sterile. The line was continued by others.[1689] The Peruvian Incas, but not other Peruvians, married their sisters.[1690] In the Vedic mythology the first man and king of the dead, Yama, had his sister, Yami, to wife. In a hymn these two are represented as discussing the propriety of marriage between brother and sister. This shows the revolt of later mores against what once was not tabooed.[1691] The scholars think that Herodotus (III, 31), by his story of the question whether Cambyses could marry his sister, shows that such marriages were not allowed amongst the ancient Persians. They are mentioned as a usage of the magi. In the Avesta they are prescribed as holy and meritorious. They are enjoined by religion. They were practiced by the Sassanids,[1692] although in the Dinkart version of the law they are apologized for and to some extent disavowed.[1693] After the time of Cambyses such marriages occurred, especially in the royal family. They now occur amongst the Persians.[1694]