IF JUST the idea of marrying your cousin sends you into a tailspin, you might be surprised to learn how prolific the practice is today.
Across the globe, more than 10 per cent of marriages are between first or second cousins.
It is widely known that the children of first-cousin marriages are at an increased risk of having genetic disorders, and yet the practice is still strongly favoured in places such as the Middle East and South Asia.
Even in the UK, there is no legal bar to two cousins getting married.
Some cultures continue to practice cousin marriage with the understanding it keeps values intact, preserves family wealth, keeps family geographically close, maintains tradition, and strengthens family ties.
Meanwhile, in jurisdictions including mainland China, Taiwan, North Korea, South Korea, the Philippines, and 24 of the 50 United States, it is legally prohibited.
These are the places where it is still legal for cousins to marry:
Marriage between cousins has been allowed in the Middle East for all recorded history.
In central Arabia, men have the right to marry their father’s brother’s daughter.
Women are not technically forced to marry their male cousins, but cannot marry anyone else without their consent.
There have been shocking incidents recorded in Iraq where men have murdered their female cousins for trying to marry someone else.
Anthropologist Ladislav Holý once said the practice was an expression of Middle Eastern preference for solidarity with one’s father’s lineage, while others have said it is adopted because it allows men to control women.
A 2009 study found that Arab countries have some of the highest rates of marriages between closely-related people in the world, and that the percentage of first cousin marriages could be up to 30 percent.
It is not a dying trend either, with Qatar, Yemen, and the United Arab Emirates now seeing increased rates of consanguinity.
An estimated 35 to 50 per cent of all sub-Saharan African populations are said to either prefer or accept cousin marriages.
Muslims in the largest ethnic group in Nigeria, Hausa, practice it preferentially and allow husbands to have multiple wives.
A 1974 study found that 51 per cent of marriages among the Yoruba people in Nigeria were between close relatives, also including uncle-niece unions.
Cousin marriage in the UK is legal and not uncommon, while in France it is legal but considered taboo and is relatively uncommon.
A study of a middle-class London population conducted in the 1960s revealed one in 25,000 marriages was between first cousins.
In Germany, it is legal but rare and controversial, and in Greece marriage to third cousins is allowed and considered favourably.
The practice was standard in Italian regions such as Calabria and Sicily, with first-cousin marriage accounting for nearly 50 per cent of all marriages in the 1900s.
The Prime Minister of the Netherlands only recently proposed a cousin marriage ban which would aim to prevent “import marriages” from other nations.
As of 2014, 19 US states allow marriages between first cousins, seven allow only some marriages between first cousins, and 24 prohibit marriages between first cousins.
Six states have outlawed first-cousin-once-removed marriages.
The two special administrative regions of China, Hong Kong and Macau, place no restrictions on marriage between cousins despite it being prohibited on the mainland.
First-cousin marriage is allowed in Japan but is less common now than it once was.
Marriage between close relatives is legal and relatively common in Afghanistan, with 46.2 per cent of unions falling in the category.
It is also legal and common in Pakistan, while attitudes vary greatly by region and culture in India.