A cousin marriage is a marriage where the spouses are cousins (i.e. people with common grandparents or people who share other fairly recent ancestors). The practice was common in earlier times and continues to be common in some societies today. In some jurisdictions such marriages are prohibited due to concerns about inbreeding. Worldwide, more than 10% of marriages are between first or second cousins. Cousin marriage is an important topic in anthropology and alliance theory.
In some cultures and communities, cousin marriages are considered ideal and are actively encouraged and expected; in others, they are seen as incestuous and are subject to social stigma and taboo. Other societies may take a neutral view of the practice, neither encouraging nor condemning it, though it is usually not considered the norm. Cousin marriage was historically practiced by Aboriginals in Australia, North America, South America, Polynesia and Melanesia.
In some jurisdictions, cousin marriage is legally prohibited: for example, first-cousin marriage in China, North Korea, South Korea, the Philippines, for Hindus in some jurisdictions of India, some countries in the Balkans, Belgium, Lithuania and 30 out of the 50 U.S. states. It is criminalized in 8 states in the US, the only jurisdictions in the world to do so. The laws of many jurisdictions set out the degree of consanguinity prohibited among sexual relations and marriage parties. Supporters of cousin marriage where it is banned may view the prohibition as discrimination, while opponents may appeal to moral or other arguments.
Opinions vary widely as to the merits of the practice. Children of first-cousin marriages have a 4–6% risk of autosomal recessive genetic disorders compared to the 3% of the children of totally unrelated parents. A study indicated that between 1800 and 1965 in Iceland, more children and grandchildren were produced from marriages between third or fourth cousins (people with common great-great- or great-great-great-grandparents) than from other degrees of separation.
History The prevalence of first-cousin marriage in Western countries has declined since the late 19th century and early 20th century.Ottenheimer 1996, pp. 58, 92Freire-Maia 1957 In the Middle East and Indian Subcontinent (except India and Nepal), cousin marriage is still strongly favored.Bittles 1994, p. 563The National 2009Bittles 2000
Cousin marriage has often been practiced to keep cultural values intact, preserve family wealth, maintain geographic proximity, keep tradition, strengthen family ties, and maintain family structure or a closer relationship between the wife and her in-laws. Many such marriages are arranged (see also articles on arranged marriage in the Indian subcontinent, arranged marriages in Pakistan, and arranged marriages in Japan).Bittles 1994, p. 567Bittles and Black 2009, Section 7
China
Confucius described marriage as "the union of two surnames".Dawson 1915, p. 143 In ancient China some evidence indicates that in some cases two clans had a longstanding arrangement whereby they would marry only members of the other clan. Some men also practiced sororate marriage, that is a marriage to a former wife's sister or a polygynous marriage to both sisters. This would have the effect of eliminating parallel-cousin marriage as an option because they would have the same surname but would leave cross-cousin marriage acceptable.Chen 1932, pp. 628–629 In the ancient system of the Erya dating from around the third century BC, the words for the two types of cross cousins were identical ( shēng), with father's brother's children ( shēng) and mother's sister's children ( cóngmǔ kūndì for boys and cóngmǔ zǐmèi for girls) both being distinct.Feng 1967, p. 37 However, whereas it may not have been permissible at that time, marriage with the mother's sister's children also became possible by the third century AD.Feng 1967, p. 44 Eventually, the mother's sister's children and cross cousins shared one set of terms, with only the father's brother's children retaining a separate set.Feng 1967, p. 38 This usage remains today, with biǎo () cousins considered "outside" and paternal táng () cousins being of the same house.Chen 1932, pp. 650–651
Anthropologist Francis L. K. Hsu described a mother's brother's daughter (MBD) as being the most preferred type of Chinese cousin marriage.Hsu 1945, p. 91 Another research describes marrying a mother's sister's daughter (MSD) as being tolerated, but a father's brother's daughter (FBD, or táng relatives in Chinese) is strongly disfavored.Zhaoxiong 2001, pp. 347–349 The last form is seen as nearly incestuous and therefore prohibited, for the man and the woman in such marriage share the same surname, much resembling sibling marriage. In Chinese culture, patrilineal ties are most important in determining the closeness of a relation.Zhaoxiong 2001, p. 355 In the case of the MSD marriage, no such ties exist, so consequently, this may not even be viewed as cousin marriage. Finally, one reason that MBD marriage is often most common may be the typically greater emotional warmth between a man and his mother's side of the family.Zhaoxiong 2001, p. 356–357 Later analyses have found regional variation in these patterns; in some rural areas where cousin marriage is still common, MBD is not preferred but merely acceptable, similar to MSD.
The following is a Chinese poem by Bai Juyi (A.D. 772–846), in which he described an inbreeding village.Chen 1932, p. 630
In some periods in Chinese history, all cousin marriage was legally prohibited, as law codes dating from the Ming dynasty (1368–1644) attest. However, enforcement proved difficult and by the subsequent Qing dynasty, the former laws had been restored.Feng 1967, p. 43 During the Qing dynasty era (1644–1912), first cousin marriage was common and prevailed after the era particularly in rural regions. By the early to mid-20th century, anthropologists described cross-cousin marriage in China as "still permissible ... but ... generally obsolete" or as "permitted but not encouraged". Eventually, in 1981, a legal ban on first-cousin marriage was enacted by the government of the People's Republic of China due to potential health concerns.
Middle East
Cousin marriage has been allowed throughout the Middle East for all recorded history.Goody, Marriage and the Family in Europe Anthropologists have debated the significance of the practice; some view it as the defining feature of the Middle Eastern kinship systemPatai while others note that overall rates of cousin marriage have varied sharply between different Middle Eastern communities.Meriwether Very little numerical evidence exists of rates of cousin marriage in the past.Holy, also Patai, p. 140
Raphael Patai reported in 1962 that, in central Arabia, a man's right to his father's brother's daughter seemed not to have been relaxed in the past hundred years. Here the girl is not forced to marry her male cousin, but she cannot marry another unless he gives consent.Patai, Golden River to Golden Road, 145–153 The force of the custom is seen in one case from Jordan when the father arranged for the marriage of his daughter to an outsider without obtaining the consent of her male cousin. When the marriage procession progressed with the bride toward the house of the bridegroom, the male cousin rushed forward, snatched away the girl, and forced her into his own house. This was regarded by all as a lawful marriage.Patai 153–161 In Iraq, the right of the cousin also traditionally was followed.Patai 166 The Syrian city of Aleppo during the 19th century featured a rate of cousin marriage among the elite of 24% according to one estimate, a figure that masked widespread variation: some leading families had none or only one cousin marriage, while others had rates approaching 70%. Cousin marriage rates were highest among women, merchant families, and older well-established families.Meriwether p. 135
In-marriage was more frequent in the late pre-Islamic Hijaz than in ancient Egypt. It existed in Medina during Muhammad's time, but at less than today's rates.Patai 141 In Egypt, estimates from the late 19th and early 20th centuries state variously that either 80% of fellahin married first cousins or two-thirds married them if they existed. One source from the 1830s states that cousin marriage was less common in Cairo than in other areas. In traditional Syria–Palestina, if a girl had no paternal male cousin (father's brother's son) or he renounced his right to her, the next in line was traditionally the maternal male cousin (mother's brother's son) and then other relatives. Raphael Patai, however, reported that this custom loosened in the years preceding his 1947 study. In ancient Persia, the Achaemenid kings habitually married their cousins and nieces,Women in Ancient Persia, 559–331 BC By Maria Brosius, p. 68 while between the 1940s and 1970s, the percentage of Iranian cousin marriages increased from 34 to 44%.Givens 1994 Cousin marriage among native Middle Eastern Jews is generally far higher than among the European Ashkenazim, who assimilated European marital practices after the diaspora.Patai, The Myth of the Jewish Race, "Cousin Marriage"
According to anthropologist Ladislav Holý, cousin marriage is not an independent phenomenon, but rather one expression of a wider Middle Eastern preference for agnatic solidarity, or solidarity with one's father's lineage. According to Holý, the oft-quoted reason for cousin marriage of keeping property in the family is, in the Middle Eastern case, just one specific manifestation of keeping intact a family's whole "symbolic capital".Holy, 110–117 Close agnatic marriage has also been seen as a result of the conceptualization of men as responsible for the control of the conduct of women.Holy, 118–120 Honor is another reason for cousin marriage: while the natal family may lose influence over the daughter through marriage to an outsider, marrying her in their kin group allows them to help prevent dishonorable outcomes such as attacks on her or her own unchaste behavior.Holy, 120–127 Pragmatic reasons for the husband, such as warmer relations with his father-in-law, and those for parents of both spouses, like reduced bride price and access to the labor of the daughter's children, also contribute.Holy, Chapter 2Patai 144–145 Throughout Middle Eastern history, cousin marriage has been both praised and discouraged by various writers and authorities.Patai 173–175
A 2009 study found that many Arab countries display some of the highest rates of consanguineous marriages in the world, and that first cousin marriages may reach 25–30% of all marriages. (Table 1). In Qatar, Yemen, and UAE, rates of consanguineous marriages are increasing in the current generation.
Middle Eastern parallel-cousin marriage Andrey Korotayev claimed that Islamization was a strong and significant predictor of parallel cousin (father's brother's daughter – FBD) marriage, bint 'amm marriage. He has shown that while a clear functional connection exists between Islam and FBD marriage, the prescription to marry a FBD does not appear to be sufficient to persuade people to actually marry thus, even if the marriage brings with it economic advantages. According to Korotayev, a systematic acceptance of parallel-cousin marriage took place when Islamization occurred together with Arabization.Korotayev A. V. Parallel Cousin (FBD) Marriage, Islamization, and Arabization // Ethnology 39/4 (2000): 395–407.
Islam forbids marrying one's nephew or niece, this can be found in the Quran 4:23 which states (translated from Arabic):