Descent
In many societies where kinship connections are important, there are rules, though they may be expressed or be taken for granted. There are four main headings that anthropologists use to categorize rules of descent. They are bilateral, unilineal, ambilineal and double descent.
Bilateral descent or two-sided descent affiliates an individual more or less equally with relatives on his father's and mother's sides. A good example is the Yakurr of the Crossriver state of Nigeria.
Unilineal rules affiliates an individual through the descent of one sex only, that is, either through males or through females. They are subdivided into two: patrilineal (male) and matrilineal (female). Most societies are patrilineal. Examples of a matrilineal system of descent are the Nyakyusa of Tanzania and the Nair of India. Many societies that practise a matrilineal system often have a matrilocal residence but men still exercise significant authority.
Ambilineal (or Cognatic) rule affiliates an individual with kinsmen through the father's or mother's line. Some people in societies that practise this system affiliate with a group of relatives through their fathers and others through their mothers. The individual can choose which side he wants to affiliate to. The Samoans of the South Pacific are an excellent example of an ambilineal society. The core members of the Samoan descent group can live together in the same compound.
Double descent (or double unilineal descent) refers to societies in which both the patrilineal and matrilineal descent group are recognized. In these societies an individual affiliates for some purposes with a group of patrilineal kinsmen and for other purposes with a group of matrilineal kinsmen. Individuals in societies that practice this are recognized as a part of multiple descent groups, usually at least two. The most widely known case of double descent is the Afikpo of Imo state in Nigeria. Although patrilineage is considered an important method of organization, the Afikpo considers matrilineal ties to be more important.
A descent group is a social group whose members talk about common ancestry. A unilineal society is one in which the descent of an individual is reckoned either from the mother's or the father's line of descent. Matrilineal descent is based on relationship to females of the family line. A child would not be recognized with their father's family in these societies, but would be seen as a member of their mother's family's line. Simply put, individuals belong to their mother's descent group. Matrilineal descent includes the mother's brother, who in some societies may pass along inheritance to the sister's children or succession to a sister's son. Conversely, with patrilineal descent, individuals belong to their father's descent group. Children are recognized as members of their father's family, and descent is based on relationship to males of the family line. Societies with the Iroquois kinship system, are typically unilineal, while the Iroquois proper are specifically matrilineal.
In a society which reckons descent bilaterally (bilineal), descent is reckoned through both father and mother, without unilineal descent groups. Societies with the Inuit system, like the Inuit, Yupik, and most Western societies, are typically bilateral. The egocentric kindred group is also typical of bilateral societies. Additionally, the Batek people of Malaysia recognize kinship ties through both parents' family lines, and kinship terms indicate that neither parent nor their families are of more or less importance than the other.
Some societies reckon descent patrilineally for some purposes, and matrilineally for others. This arrangement is sometimes called double descent. For instance, certain property and titles may be inherited through the male line, and others through the female line.
Societies can also consider descent to be ambilineal (such as Hawaiian kinship) where offspring determine their lineage through the matrilineal line or the patrilineal line.
A lineage is a unilineal descent group that can demonstrate their common descent from a known apical ancestor. Unilineal lineages can be matrilineal or patrilineal, depending on whether they are traced through mothers or fathers, respectively. Whether matrilineal or patrilineal descent is considered most significant differs from culture to culture.
A clan is generally a descent group claiming common descent from an apical ancestor. Often, the details of parentage are not important elements of the clan tradition. Non-human apical ancestors are called totems. Examples of clans are found in Chechen, Chinese, Irish, Japanese, Polish, Scottish, Tlingit, and Somali societies.
A phratry is a descent group composed of three or more clans each of whose apical ancestors are descended from a further common ancestor.
If a society is divided into exactly two descent groups, each is called a moiety, after the French word for half. If the two halves are each obliged to marry out, and into the other, these are called matrimonial moieties. Houseman and White (1998b, bibliography) have discovered numerous societies where kinship network analysis shows that two halves marry one another, similar to matrimonial moieties, except that the two halves—which they call matrimonial sides—are neither named nor descent groups, although the egocentric kinship terms may be consistent with the pattern of sidedness, whereas the sidedness is culturally evident but imperfect.
The word deme refers to an endogamous local population that does not have unilineal descent. Thus, a deme is a local endogamous community without internal segmentation into clans.
In some societies kinship and political relations are organized around membership in corporately organized dwellings rather than around descent groups or lineages, as in the "House of Windsor". The concept of a house society was originally proposed by Claude Lévi-Strauss who called them "sociétés à maison". The concept has been applied to understand the organization of societies from Mesoamerica and the Moluccas to North Africa and medieval Europe. Lévi-Strauss introduced the concept as an alternative to 'corporate kinship group' among the cognatic kinship groups of the Pacific region. The socially significant groupings within these societies have variable membership because kinship is reckoned bilaterally (through both father's and mother's kin) and comes together for only short periods. Property, genealogy and residence are not the basis for the group's existence.
