PATRILINEAL DESCENT AND THE PERMUTATIONS OF DESCENT SYSTEMS

There are several reasons why it is useful to consider systems where patrilineal descent groups predominate before going on to look at societies where descent groups are matrilineally or cognatically, and then at more complex or specialized system. This is an anthropologically traditional way of viewing descent, though one that has sexistovertones and can well raise feminist eyebrows or wrath. There are a better reasons than tradition for this approach.

First of all, patrilineal descent groupings are far more common than matrilineal ones. Keeping in mind the dangers of classing a society as patrilineal or matrilineal, it is worth looking at some statistics.
That patrilineal systems predominate statistically reflects first some ecological pressures. Predominantly pastoral societies, with a male dominated division of labor and usually considerable mobility, are characteristically patrilineally organized.

A HYPOTHETICAL PATRILINEAL DESCENT SYSTEM
There are many variations in this pattern in the tribal world, and we will glimpse a few of them. First, some important futures of patrilineal descent systems can be illustrated in terms of the Smiths and Joneses, and some needed technical terms defined.
First of all, note that the Elm Street Smiths are related by common descent: but so too are all the Smiths in the neighborhood, all the Smiths in the district, and according to tradition in town. That is descent categories can be formed at higher and higher levels.
Such descent groups and categories, based on descent from more and more remote ancestors, are called segmentary (Smith 1956). A part of a wider hypothetical genealogy of Smiths is illustrated in figure 9.
These systems are called segmentary because they are divided at each level into segments. Their genealogical structure is hierarchical.
It works because what looks at any single point in time as though it were stable and permanent arrangement of people, territories, and genealogical connections is in fact only a temporary crystallization.

LINEAGES AND CLANS
A unilineal descent group whose members trace their descent from a known ancestor and know the genealogical connections to that ancestor is technically called a lineage. In the case of the patrilineal Smiths and Joneses we can call the descent groupings patrilineages in a matrilineal system, they are called matrilineages. Note that lineages can occur at different hierarchical levels in a segmentary system. In segmentary systems, such “nested lineages” can be categorized as “maximal”, “medial”, and “minimal”. Lineages are distinguished however from unilineal descent groupings whose members believe they are descended from a common ancestor, but do not know the genealogical connections. Such categories or groups are called clans. Thus all the Smiths in our town form a patrilineal clan. When a society is conceived as divided into two parts, determined by descent these are called moieties (patri-moieties if one belongs to one’s father’s side, matri-moieties if one belongs to one’s mother’s side ). Finally, when several clans are allied into a single category, and there are three or more such clusters, the clusters are called phratries (sing phratry).
LOCAL GROUPS AND DESCENT GROUPS
Another important feature of a system of unilineal descent groups is that for any particular corporation and its territory there are two separate categories for membership. This can be clearly illustrated for the Elm Street Smiths.
In a patrilineal system, the relative strength of ties between a woman and her husband and between a woman and her brother is always important. In some systems, a woman retains very strong ties to her lineage, and her father or brother retain strong legal rights over her.
Much confusion in the anthropology of social organization has resulted from a failure to keep straight the difference between a descent group, which does not include in marrying spouses but excludes out marrying descent group members. Usually both are important. The trick is to find out in what contexts, and in what ways, and to keep from blurring them together as “the localized descent group” (Keesing 1971).