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:
There emerged a preference for maternal custody of children after divorce, as custody was more often settled based on the best interests of the child, rather than strictly awarding custody to the parent of greater financial means.
Both spouses have a formal duty of spousal support in the event of divorce (no longer just the husband)[clarification needed]
Out of wedlock children have the same rights of support as legitimate children
In most countries, rape within marriage is illegal and can be punished
Spouses may no longer physically abuse their partners and women retain their legal rights upon marriage.
In some jurisdictions, property acquired since marriage is not owned by the title-holder. This property is considered marital and to be divided among the spouses by community property law or equitable distribution via the courts.
Marriages are more likely to be a product of mutual love, rather than economic necessity or a formal arrangement among families.
Remaining single by choice is increasingly viewed as socially acceptable and there is less pressure on young couples to marry. Marriage is no longer obligatory.
Interracial marriage is no longer forbidden.
Fathers, upon divorce, are held financially responsible for their children.
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.
Asia and Africa
Nubian wedding with some international modern touches, near Aswan, Egypt
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.
Polygamy, monogamy, and polyandry
Polyandry (a woman having multiple husbands) occurs very rarely in a few isolated tribal societies. 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.
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.
Christian acceptance of monogamy
In the Christian society, 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.
Several exceptions have existed for various Biblical figures, incestuous relationships such as Abraham and Sarah , Nachor and Melcha , Lot and his Daughters Amram and Jochabed , and more
Christianity for the past several years has continued to insist on monogamy as an essential of marriage.
Contemporary Western societies
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, which involves entering into successive marriages over time. Serial monogamy is also sometimes used to refer to cases where the couples cohabitate without getting married.