topic: Marriage
Socially sanctioned union that reproduces the family. In all societies the choice of partners is generally guided by rules of exogamy (the obligation to marry outside a group); some societies also have rules of endogamy (the obligation to marry within a group). These rules may be prescriptive or, as in the case of the incest taboo, proscriptive; they generally apply to kinship groups such as clan or lineage; residential groups; and social groups such as the ethnic group, caste, or class.
In many societies marriage links not just nuclear families but larger social formations as well. Some endogamous societies are divided into different exogamous groups (such as clans or lineages): Men form alliances through the exchange of women, and the social organization regulates these alliances through marriage rules. In some cases, two men from different groups exchange sisters for brides. Other instances involve an adult man marrying the young or infant daughter of another man; sexual relations would be deferred for many years, but the two men will have formed a strong bond. Marriages are often arranged by the families through the services of a matchmaker or go-between, and commence with a ritual celebration, or wedding. Some cultures practice trial marriage; the couple lives together before deciding whether they should marry. Society generally prescribes where newlywed couples should live: In patrilocal cultures, they live with or near the husband's family; in matrilocal ones, with or near the wife's family. Under neolocal residence, the couple establishes their own household.
Although marriage tends to be regarded in many places as a permanent tie, divorce is allowed in most modern societies. The causes of divorce vary, but adultery, desertion, infertility, failure to provide the necessities of life, mistreatment, and incompatibility are the most common. Civil unions are now permitted in Western countries, but for nearly a thousand years marriage in the Western world was a religious contract. The Christian church undertook its supervision in the 9th cent., when newlywed couples instituted the practice of coming to the church door to have their union blessed by the priest. Eventually the church regulated marriage through canon law. In contemporary N Europe marriage has lost some of importance, especially as social legislation has emphasized assuring equal financial benefits and legal standing to children born to unwed parents.
Monogamy (the union of one wife to one husband) is the prevalent form almost everywhere. Polygyny (or polygamy; having several wives at one time), however, has been a prerogative in many societies. It is commonly found where the value of women's labor is high and may be practiced as a way of acquiring allies: A man may cement his bonds with several other men by marrying their sisters or daughters. Polyandry (having several husbands at one time) is rare, having occurred infrequently in Tibetan society, among the Marquesas of Polynesia, and among certain hill tribes in India. People who enjoy only a marginal subsistence may practice polyandry as a way of limiting births. It is also practiced where brothers must work together to sustain one household; they share one wife. The custom of marrying a widow to her late husband's brother is known as levirate marriage and was common among the ancient Hebrews. In sororate marriages a widower marries his deceased (or barren) wife's sister. The levirate and the sororate occur in societies where marriage is seen to create an alliance between groups; the deceased spouse's group has a duty to provide a new spouse to the widow or widower, thereby preserving the alliance. In recent years many gay-rights groups have sought official recognition of same-sex couples that would be comparable to marriage.