Generally, there are four overlapping definitions. Murdock, of 1, societies from around the world noted, were monogamous; had occasional polygyny; had more frequent polygyny; and 4 had polyandry.
This can be interpreted as a form of plural mating, as are those societies dominated by female-headed families in the Caribbean , Mauritius and Brazil where there is frequent rotation of unmarried partners. The Standard Cross-Cultural Sample describes the amount of extramarital sex by men and women in over 50 pre-industrial cultures. The amount of extramarital sex by women is described as "universal" in 6 cultures, "moderate" in 23 cultures, "occasional" in 9 cultures, and "uncommon" in 15 cultures.
These findings support the claim that the reported amount of extramarital sex differs across cultures and across genders. Recent surveys conducted in non-Western nations have also found cultural and gender differences in extramarital sex. Many surveys asking about extramarital sex in the United States have relied on convenience samples. A convenience sample means surveys are given to whoever happens to be easily available e.
Convenience samples do not accurately reflect the population of the United States as a whole, which can cause serious biases in survey results. It should not be surprising, therefore, that surveys of extramarital sex in the United States have produced widely differing results.
Three studies have used nationally representative samples. That study was funded by the National Institute of Mental Health. Yet, the incidence of sexual monogamy varies across cultures. People in some cultures are more sexually monogamous than people in other cultures. Extrapair paternity is when offspring raised by a monogamous pair come from the female mating with another male.
Rates of extrapair paternity have not been extensively studied in people. Many reports of extrapair paternity are little more than quotes based on hearsay, anecdotes, and unpublished findings. The median rate of extrapair paternity was 1. A separate review of 17 studies by Bellis, Hughes, Hughes, and Ashton found slightly higher rates of extrapair paternity. A range of 1.
A review paper, surveying 67 other studies, reported rates of extrapair paternity, in different societies, ranging from 0.
When attempts are made to try to study medical afflictions and their genetic components, it becomes very important to understand nonpaternity rates and pedigree errors. There are numerous software packages and procedures that exist for correcting research data for pedigree errors.
In any species, there are three main aspects that combine to promote a monogamous mating system: Paleoanthropological estimates of the time frame for the evolution of monogamy are primarily based on the level of sexual dimorphism seen in the fossil record because, in general, the reduced male-male competition seen in monogamous mating results in reduced sexual dimorphism.
While female effective population size the number of individuals successfully producing offspring thus contributing to the gene pool , as indicated by mitochondrial-DNA evidence, increased around the time of human not hominid expansion out of Africa about 80,—, years ago, male effective population size, as indicated by Y-chromosome evidence, did not increase until the advent of agriculture 18, years ago.
This means that before 18, years ago, many females would be reproducing with the same few males. The castle in the background is Lusignan. This is a detail from the painting for March. Despite the human ability to avoid sexual and genetic monogamy, social monogamy still forms under many different conditions, but most of those conditions are consequences of cultural processes. For example, anthropologist Jack Goody 's comparative study utilizing the Ethnographic Atlas demonstrated that monogamy is part of a cultural complex found in the broad swath of Eurasian societies from Japan to Ireland that practice social monogamy, sexual monogamy and dowry i.
In plough agriculture farming is largely men's work and is associated with private property; marriage tends to be monogamous to keep the property within the nuclear family. Close family endogamy are the preferred marriage partners to keep property within the group.
Low, culture would appear to have a much larger impact on monogamy in humans than the biological forces that are important for non-human animals. Laura Betzig argues that in the six large, highly stratified early states, commoners were generally monogamous but that elites practiced de facto polygyny. In the patriarchal society of Mesopotamia the nuclear family was called a "house". In order "to build a house" a man was supposed to marry one woman and if she did not provide him with offspring, he could take a second wife.
The Code of Hammurabi states that he loses his right to do so if the wife herself gives him a slave as concubine. The position of the second wife was that of a "slave girl" in respect to the first wife, as many marriage contracts explicitly state. This may suggest that some men abandoned first wives of a low social status and married women of higher status in order to further their careers although even then they lived with only one wife.
Egyptian women had right to ask for a divorce if her husband took a second wife. Many tomb reliefs testify to monogamous character of Egyptian marriages, officials are usually accompanied by a supportive wife.
The instruction texts belonging to wisdom literature, e. Instruction of Ptahhotep or Instruction of Any , support fidelity to monogamous marriage life, calling the wife a Lady of the house. The Instruction of Ankhsheshonq suggests that it is wrong to abandon a wife because of her barrenness. In Israel's pre-Christian era, an essentially monogamous ethos underlay the Jewish creation story Gn 2 and the last chapter of Proverbs.
Examples of these documents were found in Elephantine. They resemble those found in neighbouring Assyria and Babylonia.
Christianity adopted a similar attitude cf. The wisdom books e. Book of Wisdom , which provides a picture of the society, Sirach , Proverbs , Qohelet portray a woman in a strictly monogamous family cf.
The Book of Tobias speaks solely of monogamous marriages. Also prophets have in front of their eyes monogamous marriage as an image of the relationship of God and Israel. Roland de Vaux states that "it is clear that the most common form of marriage in Israel was monogamy". Some sages condemned marriage to two wives even for the purpose of procreation Ketubot 62b. Ammi, an amora states: Whoever takes a second wife in addition to his first one shall divorce the first and pay her kettubah Yevamot 65a Roman customs, which prohibited polygamy, may have enhanced such an attitude[ original research?
Jesus avoids entangling himself in juridical or casuistic controversies; instead, he appeals twice to the "beginning". By doing so, he clearly refers to the relevant words of Genesis, which his interlocutors also know by heart. The United Nations joined these efforts in when the General Assembly adopted the Convention on the Elimination of All Forms of Discrimination Against Women , an international bill of rights for women that over nations have agreed to implement.
Article 16 of the Convention requires nations to give women and men equal rights in marriage. Polygamy is interpreted as inconsistent with Article 16 when it extends the right of multiple spouses to men but not to women. The United Nations is thus working through the Convention and CEDAW to promote women's equality by making monogamy the only legal form of marriage worldwide. People's Republic of China[ edit ] Main article: Marriage in the People's Republic of China The founders of Communism believed monogamy oppressed women and had no place in communist society.
The newly formed Communist government established monogamy as the only legal form of marriage. The new democratic marriage system was based on the free choice of couples, monogamy, equal rights for both sexes, and the protection of the lawful interests of women. It abolished the begetting of male offspring as the principal purpose of marriage and weakened kinship ties which reduced the pressure on women to bear many children, especially sons.
With arranged marriages prohibited, young women could choose their own marriage partners, share the financial cost of setting up a new household, and have equal status in household and family decision-making. While the protocol does not suggest making polygamous marriage illegal, article 6 of the protocol states that "monogamy is encouraged as the preferred form of marriage and that the rights of women in marriage and family, including in polygamous marital relationships are promoted and protected.
Varieties in biology[ edit ] Recent discoveries have led biologists to talk about the three varieties of monogamy: The distinction between these three are important to the modern understanding of monogamy.