Cousin marriage is one of those topics that can start a loud argument before the first sentence is finished. In some countries, it is viewed as a private family tradition. In others, it is seen mainly through the lens of public health, genetics, women’s choice, and changing social norms.
But across parts of South Asia, the Middle East, North Africa, and Central Asia, marriages between relatives remain far more common than many outsiders realize.
Researchers often use the term consanguineous marriage to refer to marriage between people who are biologically related, usually second cousins or closer.
That category can include first cousins, double first cousins, first cousins once removed, and second cousins.
Because countries and studies measure it differently, the numbers below should be read as reported estimates and ranges, not as a perfect global league table. Still, the pattern is clear: in several countries, marrying within the extended family remains a major part of the marriage culture.
Why Cousin Marriage Remains Common in Some Places
For many families, cousin marriage is not just about romance. It is tied to land, inheritance, family trust, dowry negotiations, tribal identity, and the belief that a known family is safer than a stranger’s family.
In some communities, marrying within the family is seen as a way to protect property, strengthen bonds, and reduce uncertainty between in-laws.
Researchers have also linked higher rates to rural life, traditional family systems, lower mobility, and limited marriage options outside the extended kin network.
But the health debate is impossible to ignore. Studies note that first-cousin unions can increase the chance that children inherit rare recessive genetic disorders, because both parents may carry the same hidden gene variant from a shared ancestor.
One major review estimated that the risk of birth defects among children of first cousins is about 2 to 2.5 times the general population rate, while another estimate placed the extra risk at 1.7% to 2.8% above the background risk.
The 10 Countries Most Often Linked to High Cousin-Marriage Rates
Pakistan
Pakistan is frequently identified as one of the countries with the highest reported levels of cousin marriage worldwide.
Research has found that marriages between relatives are deeply connected to family structures, especially in communities where extended families play a central role in social and economic life.
Older studies estimated that when second cousins are included, consanguineous marriages accounted for around 61.2% of marriages in Pakistan.
Other research has continued to describe the country as having one of the highest rates globally, with some estimates suggesting that close-relative marriages account for a significant share of all unions.
The tradition is especially common in certain rural and tribal communities, where family relationships, inheritance, and social networks strongly influence marriage decisions. In many cases, families see marriage within the extended family as a way to maintain trust and preserve connections between generations.
Saudi Arabia
Saudi Arabia is another country frequently mentioned in discussions about high cousin-marriage rates. In many Saudi communities, marriage has traditionally been viewed not only as a union between two individuals but also as an alliance between families.
Research has reported overall consanguinity rates ranging from 42.1% to 66.7%, showing that marriage between relatives remains common in many parts of the country.
Several factors have contributed to the persistence of the practice. Family reputation, tribal connections, inheritance traditions, and cultural expectations have historically played important roles in marriage decisions. For some families, keeping marriage within known relatives is seen as a way to protect family identity and maintain close relationships.
Kuwait
Kuwait has one of the highest reported rates of cousin marriage in the Gulf region, although estimates vary significantly between studies and communities. Research has reported overall consanguinity rates ranging from 22.5% to 64.3%.
The wide range reflects the diversity of Kuwaiti society. Some families continue to strongly value marriages within the extended family, while others have moved toward broader social networks and marriages outside their relatives.
Historically, family connections have been important in Kuwaiti society. Marriage between relatives was often viewed as a way to strengthen family relationships, maintain social stability, and preserve wealth across generations.
Sudan
Sudan is among the countries with some of the highest reported rates of consanguineous marriage. Research has estimated overall rates ranging from 44.2% to 63.3%.
In Sudanese communities, extended family relationships often play a central role in daily life. Marriage decisions may involve not only individuals but also parents, relatives, and wider family networks.
For many families, marrying within the extended family is associated with trust and familiarity. Relatives often share similar cultural backgrounds, traditions, and expectations, which some families believe can make marriage easier to manage.
Iraq
Iraq has long been recognized as a country where cousin marriage remains widespread. Studies have reported overall consanguinity rates ranging from 47% to 60%.
Family structure has historically been a major influence on marriage decisions in Iraq. In many communities, relatives are closely connected through social, economic, and cultural ties, making marriage within the extended family a familiar practice.
First-cousin marriages have traditionally been common, particularly among families seeking to strengthen relationships between relatives or maintain family property and traditions.
Oman
Oman has one of the highest reported rates of cousin marriage in the Gulf region, with research estimating overall consanguinity at approximately 56.3%.
Family relationships remain highly valued in Omani society, and marriage has traditionally been associated with maintaining strong bonds among relatives and communities.
Many families view marriage within the extended family as beneficial because relatives already understand each other’s backgrounds, values, and social expectations.
However, Oman has undergone significant economic and social changes in recent decades. Education, employment opportunities, and urban growth have expanded social networks, creating more opportunities for people to meet partners outside their families.
Qatar
Qatar has also recorded high levels of cousin marriage, with reported overall consanguinity rates around 54%. The practice has historically been influenced by family traditions, tribal relationships, and the emphasis on maintaining strong connections among relatives.
In Qatari society, extended families often remain closely connected, and marriage decisions can involve wider family considerations. For some households, marrying within the family continues to represent stability and trust.
At the same time, Qatar’s rapid modernization has introduced major social changes. Higher education levels, international experiences, and greater interaction with diverse cultures have influenced younger generations’ views on marriage.
United Arab Emirates
The United Arab Emirates has reported overall consanguinity rates ranging from 40% to 54.2%. The UAE presents an interesting example of tradition existing alongside rapid modernization.
While the country has become one of the world’s most internationally connected societies, family traditions remain important in many communities.
Historically, marriages between relatives helped maintain family relationships, preserve cultural identity, and strengthen connections between households.
However, the rise of cities such as Dubai and Abu Dhabi has created more diverse social environments. Younger generations increasingly interact with people from different backgrounds through education and work.
Mauritania
Mauritania has reported a consanguinity rate of approximately 47.2%, placing it among countries with notably high levels of cousin marriage. In Mauritania, family lineage, social connections, and community relationships have traditionally played important roles in marriage decisions.
For some families, marrying relatives helps preserve cultural traditions and maintain close relationships between extended family members.
The practice is particularly connected to communities where family identity and ancestry hold strong importance. However, like many countries experiencing social change, Mauritania has seen gradual shifts as education, migration, and urbanization influence younger generations.
Afghanistan
Afghanistan has also been identified among countries with high reported levels of cousin marriage. One study estimated national consanguinity at 46.2%, with regional differences ranging from 38.2% in Kabul to 51.2% in Bamyan.
Marriage in Afghanistan has traditionally been strongly connected to family networks, community relationships, and cultural traditions. In many areas, families have historically preferred marriages between relatives because they already understand each other’s backgrounds and social standing. First-cousin marriages have been particularly common, followed by other forms of close-relative unions.
The Bigger Story Behind the Numbers
The story of cousin marriage is not simply about statistics. It reflects how societies balance tradition, family expectations, cultural identity, and modern ideas about personal choice.
In many communities, cousin marriage has survived because it serves social purposes beyond the relationship between two individuals. It can strengthen family ties, protect wealth, and maintain traditions that have existed for generations.
At the same time, changing lifestyles are reshaping marriage patterns. Education, technology, migration, and greater social interaction are giving younger generations more opportunities to meet partners outside traditional family networks.
The debate around cousin marriage will likely continue because it sits at the intersection of culture, health, and individual freedom. For some families, it represents history and connection. For health experts, it represents an opportunity for education and informed decision-making.
The future of cousin marriage in many countries may depend on how societies balance respect for tradition with access to knowledge, healthcare, and personal choice.
