Preferential marriages are also often used as a device to promote inters familial cordiality. The practice of being an actual or potential mate for a woman to her husband’s brothers is called Levirate.
Societies practicing fraternal polyandry are a case in point. The practice as a preferred rule is normally observable in a large number of societies where in the event of the death of husband a widow marries his brother (younger or elder).
As a customary rule, it is obligatory in these social on the part of the brothers, of the deceased husband to marry the widow. In case she marries the younger brother of her husband, it is called junior levirate.
If she marries the elder brother of deceased husband, it is called as senior levirate. At times, in some societies, the widow may simply be adopted in the name of the deceased brother so that the children born to this union are consider as the children of the deceased husband.
The husband of a barren woman or a deceased wife marrying her sister is called Sorority. In the former case, at least some of the children born out of this union may be considered as the children of the first wife.
A man having more than one wife being sisters among themselves is known as sorrel polygon. Both, levirate and sorority attest the importance of marriage as an alliance between two groups.
Death does not dissolve the marriage contract. They emphasize the inter Familial obligations and the recognition of marriage as a bond between two families and not only between two individuals. All forms of preferential or prescribed forms of mating limit the numb of possible martial linkages.
According to Levi-Strauss, the main purpose served by these prefers or prescribed forms of marriage is to strengthen the solidarity within a tribe. However, others have very much doubted the primitive people’s ability of understanding what is good for them. Probably psychological-emotional concerns as well as other features of their society might have leaded these rules to be become operative.
4. Parallel Cousin Marriage:
The children of two brothers or of two sisters are parallel cousins. With only a few exception parallel cousin marriage is prohibited in all societies the world over. But a few societies practice parallel cousin marriage. It is not only practised customarily but also a preferred form of marriage in them.
Among these societies, nuclear family exogamy is associated with male-descent groin endogamy. It is widely practised by pastoral nomadic Muslim Arabs. They are fighting predation pastorals with low level of political organization. There are to main functions of this type of marriage among them.
It consolidates their man power, significant in the context of nomadic and fighting tradition. Also, marrying in a descent group consolidates their property-mainly in to form of their live stocks. It also re-enforces matrilineal authority. The system finds favour with in the
organic acceptance of marriage between parallel cousins or even between half siblings. Fredrik Barth, in one of his studies among the Kurds has observed that among the village settled farmers of Middle East, lineage endogamy is replaced by village endogamy. Another instance is provided by the royal families in ancient Egypt who preferred brother sister marriage to avoid.