The type, functions, and characteristics of marriage vary from culture to culture, and can change over time.
In the Americas and Europe, in the 21st century, legally recognized marriages are formally presumed to be monogamous (although some pockets of society accept polygamy socially, if not legally, and some couples choose to enter into open marriages). In these countries, divorce is relatively simple and socially accepted. In the West, the prevailing view toward marriage today is that it is based on a legal covenant recognizing emotional attachment between the partners and entered into voluntarily.
In the West, marriage has evolved from a life-time covenant that can only be broken by fault or death to a contract that can be broken by either party at will. Other shifts in Western marriage since World War I include:
Marriage for immigration purposes is sometimes practiced by international students who are seeking to migrate to countries such as Australia, where additional points required for immigration are awarded for marriage within the country.
Some societies permit polygamy, in which a man could have multiple wives; even in such societies however, most men have only one. In such societies, having multiple wives is generally considered a sign of wealth and power. The status of multiple wives has varied from one society to another.
In Imperial China, formal marriage was sanctioned only between a man and a woman, although among the upper classes, the primary wife was an arranged marriage with an elaborate formal ceremony while concubines could be taken on later with minimal ceremony. After the rise of Communism, only strictly monogamous marital relationships are permitted, although divorce is a relatively simple process.
Polyandry (a woman having multiple husbands) occurs very rarely in a few isolated tribal societies with limited resources. These societies include some bands of the Canadian Inuit, although the practice has declined sharply in the 20th century due to their conversion from tribal religion to Christianity by Moravian missionaries. Additionally, the Spartans were notable for practicing polyandry. Spartan polyandry often took the form of adelphic polyandry (where the husbands are all biological brothers).
Societies which permit group marriage are extremely rare, but have existed in Utopian societies such as the Oneida Community.
Today, many married people practice various forms of consensual nonmonogamy, including polyamory and swinging. These people have agreements with their spouses that permit other intimate relationships or sexual partners. Therefore, the concept of marriage need not necessarily hinge on sexual or emotional monogamy.
In the Christian tradition, a "one man one woman" model for the Christian marriage was advocated by Saint Augustine (354-439 AD) with his published letter The Good of Marriage. To discourage polygamy, he wrote it "was lawful among the ancient fathers: whether it be lawful now also, I would not hastily pronounce. For there is not now necessity of begetting children, as there then was, when, even when wives bear children, it was allowed, in order to a more numerous posterity, to marry other wives in addition, which now is certainly not lawful." (chapter 15, paragraph 17) Sermons from St. Augustine's letters were popular and influential. In 534 AD Roman Emperor Justinian criminalized all but monogamous man/woman sex within the confines of marriage. The Justinian Code was the basis of European law for 1,000 years.
Christianity has continued to insist on monogamy as an essential of marriage.
In 21st century Western societies, bigamy is illegal and sexual relations outside marriage are generally frowned-upon, though there is a minority view accepting (or even advocating) open marriage.
However, divorce and remarriage are relatively easy to undertake in these societies. This has led to a practice called serial monogamy. "Serial monogamy" involves entering into successive marriages over time. Serial monogamy is also sometimes used to refer to cases where the couples cohabitate without getting married.
Some parts of India follow a custom in which the groom is required to marry with an auspicious plant called Tulsi before a second marriage to overcome inauspicious predictions about the health of the husband. This also applies if the prospective wife is considered to be 'bad luck' or a 'bad omen' astrologically. However, the relationship is not consummated and does not affect their ability to remarry later. One should note that this is not a norm found across the entire Indian sub-continent.
In the state of Kerala, India, the Nambudiri Brahmin caste traditionally practiced henogamy, in which only the eldest son in each family was permitted to marry. The younger children could have sambandha (temporary relationship) with Kshatriya or Nair women. This is no longer practiced, and in general the Nambudiri Brahmin men marry only form the Nambudiri caste and Nair women prefer to be married to Nair men.
In Mormonism, a couple may seal their marriage "for time and for all eternity" through a "sealing" ceremony conducted within LDS Temples. The couple is then believed to be bound to each other in marriage throughout eternity if they live according to their covenants made in the ceremony. Mormonism also allows living persons to act as proxies in the sealing ceremony to "seal" a marriage between ancestors who have been dead for at least one year and who were married during their lifetime. According to LDS theology, it is then up to the deceased individuals to accept or reject this sealing in the spirit world before their eventual resurrection. A living person can also be sealed to his or her deceased spouse, with another person (of the same sex as the deceased) acting as proxy for that deceased individual.
Other unusual variations include marriage between a living human and a ghost (Taiwan), a living human and a recently-deceased human with whom they were emotionally involved (France), and between a human being and God (Catholic and Orthodox monasticism). Again, these lack the social meaning of ordinary marriage and belong rather to the realm of religion or (in the case of weddings of dogs to other dogs, Kermit the Frog to Miss Piggy, and the like) pure spectacle.
One society that traditionally did without marriage entirely was that of the Na of Yunnan province in southern China. According to anthropologist Cia Hua, sexual liaisons among the Na took place in the form of "visits" initiated by either men or women, each of whom might have two or three partners each at any given time (and as many as two hundred throughout a lifetime). The nonexistence of fathers in the Na family unit was consistent with their practice of matrilineality and matrilocality, in which siblings and their offspring lived with their maternal relatives. In recent years, the Chinese state has encouraged the Na to acculturate to the monogamous marriage norms of greater China. Such programs have included land grants to monogamous Na families, conscription (in the 1970s, couples were rounded up in villages ten or twenty at a time and issued marriage licenses), legislation declaring frequent sexual partners married and outlawing "visits", and the withholding of food rations from children who could not identify their fathers. Many of these measures were relaxed in favor of educational approaches after Deng Xiaoping came into power in 1981.
See also the Mosuo ethnic minority of China and their practice of so-called walking marriage.
There are many terms for marriage types:
This article is based on "Types of marriages" from the free encyclopedia Wikipedia (http://en.wikipedia.org). It is licensed under the terms of the GNU Free Documentation Licencse. In the Wikipedia you can find a list of the authors by visiting the following address: http://en.wikipedia.org/w/index.php?title=Types+of+marriages&action=history