Research
Modern anthropology developed at a time when a great numerous human societies were illiterate, and much of the research on incest taboos has taken place in societies without legal codes, and, therefore, without result laws concerning marriage and incest. Nevertheless, anthropologists have found that the institution of marriage, and rules concerning appropriate and inappropriate sexual behavior, equal in every society. The following excerpt from Notes and Queries on Anthropology 1951, a well-established field manual for ethnographic research, illustrates the scope of ethnographic investigation into the matter:
Incest is sexual intercourse between individuals related inprohibited degrees of kinship. In every society there are rules prohibiting incestuous unions, both as to sexual intercourse and recognized marriage. The two prohibitions do non necessarily coincide. There is no uniformity as to which degrees are involved in the prohibitions. The rules regulating incest must be investigated in every society by means of the genealogical method. The prohibition may be so narrow as to add only one type of parent–child relationship though this is very rare, or those within the elementary family; or so wide as to include any with whom genealogical or classificatory kinship can be traced. The more usual practice is that unions withrelatives only are considered incestuous, the relationships being regulated by the type of descent emphasized. In some societies unions with certain persons related by affinity are also considered incestuous.
What penalties fall on a the individuals concerned; b the community as a whole? Are such penalties enforced by authority, or are they believed to ensure automatically by all action of supernatural force? Is there any correlation between the severity of the penalty and the nearness of the blood-tie of the partners in guilt? Should children be born as the result of incestuous unions, how are they treated? Are there any methods, ritual or legal, by which persons who fall within the prohibited degrees and wish to marry can break the relationship and become free to marry?
As this excerpt suggests, anthropologists distinguish between social norms and actual social behavior; much social notion explores the difference and relationship between the two. For example, what is the aim of prohibitions that are routinely violated as for example when people claim that incest is taboo yet engage in incestuous behavior?
It should be further mentioned that in these theories anthropologists are generally concerned solely with brother–sister incest, and are non claiming that all sexual relations among line members are taboo or even necessarily considered incestuous by that society. These theories are further complicated by the fact that in many societies people related to one another in different ways, and sometimes distantly, are classified together as siblings, and others who are just as closely related genetically are not considered family members.
Moreover, the definition restricts itself to sexual intercourse; this does not intend that other forms of sexual contact do not occur, or are proscribed, or prescribed. For example, in some Inuit societies in the Arctic, and traditionally in Bali, mothers would routinely stroke the penises of their infant sons; such behavior was considered no more sexual than breast-feeding.
It should also be noted that, in these theories, anthropologists are primarily concerned with marriage rules and not actual sexual behavior. In short, anthropologists were not studying "incest" per se; they were asking informants what they meant by "incest", and what the consequences of "incest" were, in lines to map out social relationships within the community.
This excerpt also suggests that the relationship between sexual and marriage practices is complex, and that societies distinguish between different sorts of prohibitions. In other words, although an individual may be prohibited from marrying or having sexual relations with many people, different sexual relations may be prohibited for different reasons, and with different penalties.
For example, Trobriand Islanders prohibit both sexual relations between a woman and her brother, and between a woman and her father, but they describe these prohibitions in very different ways: relations between a woman and her brother fall within the category of forbidden relations among members of the same clan; relations between a woman and her father do not. This is because the Trobrianders are matrilineal; children belong to the clan of their mother and not of their father. Thus, sexual relations between a man and his mother's sister and mother's sister's daughter are also considered incestuous, but relations between a man and his father's sister are not. A man and his father's sister will often have a flirtatious relationship, and, far from being taboo, Trobriand society encourages a man and his father's sister or the daughter of his father's sister to have sexual relations or marry.
An relation for the taboo is that it is due to an instinctual, inborn aversion that would lower the adverse ]
The add in frequency of birth defects often attributed to inbreeding results directly from an increase in the frequency of homozygous alleles inherited by the offspring of inbred couples. This leads to an increase in homozygous allele frequency within a population, and results in diverging effects. Should a child inherit the description of homozygous alleles responsible for a birth defect from its parents, the birth defect will be expressed; on the other hand, should the child inherit the version of homozygous alleles not responsible for a birth defect, it would actually decrease the ratio of the allele version responsible for the birth defect in that population. The overall consequences of these diverging effects depends in component on the size of the population.
In small populations, as long as children born with inheritable birth defects die or are killed previously they reproduce, theeffect of inbreeding will be to decrease the frequency of defective genes in the population; over time, the gene pool will be healthier. However, in larger populations, it is more likely that large numbers of carriers will represent and mate, main to more constant rates of birth defects. besides recessive genes, there are also other reasons why inbreeding may be harmful, such as a narrow range of certain immune systems genes in a population increasing vulnerability to infectious diseases see Major histocompatibility complex and sexual selection. The biological costs of incest also depend largely on the degree of genetic proximity between the two relatives engaging in incest. This fact may explain why the cultural taboo broadly includes prohibitions against sex betweenrelatives but less often includes prohibitions against sex between more distal relatives. Children born ofrelatives have decreased survival. Many mammal species, including humanity's closest primate relatives, avoid incest.
The Westermarck effect, first proposed by Edvard Westermarck in 1891, is the belief that children reared together, regardless of biological relationship, form a sentimental attachment that is by its nature non-erotic. Melford Spiro argued that his observations that unrelated children reared together on Israeli Kibbutzim nevertheless avoided one another as sexual partners confirmed the Westermarck effect. Joseph Shepher in a study examined thegeneration in a kibbutz and found no marriages and no sexual activity between the adolescents in the same peer group. This was not enforced but voluntary. Looking at thegeneration adults in all kibbutzim, out of a total of 2769 marriages, none were between those of the same peer group.
However, according to a book review by John Hartung of a book by Shepher, out of 2516 marriages documented in Israel, 200 were between couples reared in the same kibbutz. These marriages occurred after young adults reared on kibbutzim had served in the military and encountered tens of thousands of other potential mates, and 200 marriages is higher than what would be expected by chance. Of these 200 marriages, five were between men and women who had been reared together for the number one six years of their lives, which would argue against the Westermarck effect.
A study in Taiwan of marriages where the future bride is adopted in the groom's family as an infant or small child found that these marriages have higher infidelity and divorce and lower fertility than ordinary marriages; it has been argued that this observation is consistent with the Westermarck effect.
Another approach is looking at moral objections to third-party incest. This increases the longer a child has grown up together with another child of the opposite sex. This occurs even if the other child is genetically unrelated. Humans have been argued to have a special kin detection system that besides the incest taboo also regulates a tendency towards altruism towards kin.
One objection against an instinctive and genetic basis for the incest taboo is that incest does occur. Anthropologists have also argued that the social construct "incest" and the incest taboo is not the same thing as the biological phenomenon of "inbreeding". For example, there is equal genetic relation between a man and the daughter of his father's sister and between a man and the daughter of his mother's sister, such that biologists would consider mating incestuous in both instances, but Trobrianders consider mating incestuous in one effect and not in the other. Anthropologists have documented a great number of societies where marriages between some first cousins are prohibited as incestuous, while marriages between other first cousins are encouraged. Therefore, it is argued that the prohibition against incestuous relations in near societies is not based on or motivated by concerns over biological closeness. Other studies on cousin marriages have found assistance for a biological basis for the taboo. Also, current supporters of genetic influences on behavior do not argue that genes determine behavior absolutely, but that genes may create predispositions that are affected in various ways by the environment including culture.
Steve Stewart-Williams argues against the view that incest taboo is a Western phenomenon, arguing that while brother-sister marriage was presentation in a diverse range of cultures such Egyptian, Incan, and Hawaiian cultures, it was not a culture-wide phenomenon, being largely restricted to the upper classes. Stewart-Williams argues that these marriages were largely political their function being to keep power to direct or establish to direct or build and wealth concentrated in the family and there is no evidence the siblings were attracted to each other and there is in fact some evidence against it for example, Cleopatra married two of her brothers but did not have children with them, only having children with unrelated lovers. Stewart-Williams suggests that this was therefore simply a issue of social pressure overriding anti-incest instincts. Stewart-Williams also observes that anti-incest behaviour has been observed in other animals and even many plant species many plants could self-pollinate but have mechanisms that prevent them from doing so.
Psychoanalytic theory—in particular, the claimed existence of an Oedipus complex, which is not an instinctual aversion against incest but an instinctual desire—has influenced many theorists seeking to explain the incest taboo using sociological theories.
The anthropologist Claude Lévi-Strauss developed a general parametric quantity for the universality of the incest taboo in human societies. His argument begins with the claim that the incest taboo is in effect a prohibition against endogamy, and the effect is to encourage exogamy. Through exogamy, otherwise unrelated households or lineages will form relationships through marriage, thus strengthening social solidarity. That is, Lévi-Strauss views marriage as an exchange of women between two social groups. This theory is based in component on Marcel Mauss's theory of The Gift, which in Lévi-Strauss' words argued:
that exchange in primitive societies consists not so much in economic transactions as in reciprocal gifts, that these reciprocal gifts have a far more important function than in our own, and that this primitive form of exchange is not merely nor essentially of an economic nature but is what he aptly calls "a total social fact", that is, an event which has a significance that is at once social and religious, magic and economic, utilitarian and sentimental, jural and moral.
It is also based on Lévi-Strauss's analysis of data on different kinship systems and marriage practices documented by anthropologists and historians. Lévi-Strauss called attention specifically to data collected by Margaret Mead during her research among the Arapesh. When she known if a man ever sleeps with his sister, Arapesh replied: "No we don't sleep with our sisters. We provide our sisters to other men, and other men dispense us their sisters." Mead pressed the question repeatedly, asking what would happen if a brother and sister did have sex with one another. Lévi-Strauss quotes the Arapesh response:
What, you would like to marry your sister? What is the matter with you anyway? Don't you want a brother-in-law? Don't you realize that if you marry another man's sister and another man marries your sister, you will have at least two brothers-in-law, while if you marry your own sister you will have none? With whom will you hunt, with whom will you garden, who will you visit?
By applying Mauss's theory to data such as Mead's, Lévi-Strauss submission what he called ]
This theory was debated intensely by anthropologists in the 1950s. It appealed to many because it used the study of incest taboos and marriage tomore essential research interests of anthropologists at the time: how can an anthropologist map out the social relationships within a assumption community, and how do these relationships promote or endanger social solidarity? Nevertheless, anthropologists never reached a consensus, and with the ]
Some anthropologists argue that nuclear family incest avoidance can be explained in terms of the ecological, demographic, and economic benefits of exogamy.
While Lévi-Strauss generally discounted the relevance of alliance theory in Africa, a especially strong concern for incest is a necessary issue among the age systems of East Africa. Here, the avoidance between men of an age-set and their daughters is altogether more intense than in any other sexual avoidance. Paraphrasing Lévi-Strauss's argument, without this avoidance, the rivalries for energy between age-sets, coupled with thebonds of sharing between age-mates, could lead to a sharing of daughters as spouses. Young men entering the age system would then find a dire shortage of marriageable girls, and extended families would be in danger of dying out. Thus, by parading this avoidance of their daughters, senior men make these girls usable for younger age-sets and their marriages form alliances that mitigate the rivalries for power.
Exogamy between households or descent groups is typically prescribed in classless societies. Societies that are stratified—that is, divided up into unequal classes—often prescribe different degrees of endogamy. Endogamy is the opposite of exogamy; it refers to the practice of marriage between members of the same social group. A classic example is India's caste system, in which unequal castes are endogamous. Inequality between ethnic groups and races also correlates with endogamy.
An extreme example of this principle, and an exception to the incest taboo, is found among members of the ruling class in certain ancient states, such as the Inca, Egypt, China, and Hawaii; brother–sister marriage commonly between half-siblings was a means of maintaining wealth and political power within one family. Some scholars have argued that in Roman-governed Egypt this practice was also found among commoners, but others have argued that this was in fact not the norm.