Is it inbred to marry your cousin?
In the western world, marriage between first cousins is labeled incest or inbreeding, and in the United States the practice is banned or restricted in 31 states.
First cousins have an inbreeding coefficient of 0.0625. Anything at or above 0.0156, the coefficient for second cousins, is considered consanguineous; that includes relationships between people and their nephews and nieces.
The vast majority of children of first cousins are healthy and do not have problems due to their parents' relatedness. It is important to keep in mind that even for an unrelated couple, there is an approximately 2-3% chance that their child is born with a birth defect, genetic syndrome, or disability.
Children of first-cousin marriages have an increased risk of autosomal recessive genetic disorders, and this risk is higher in populations that are already highly ethnically similar. Children of more distantly related cousins have less risk of these disorders, though still higher than the average population.
First cousins share ~12.5% DNA
To figure out how much DNA any two relatives have, we need to figure out how much DNA in common they inherited from each shared ancestor. Let's look at first cousins. How much DNA would they share? First cousins have two shared ancestors: one Grandmother and one Grandfather.
Incest is marriage or sexual intercourse with a relative within the prohibited degree of consanguinity. In other words, incest is sexual contact between close blood relatives, including brothers and sisters, parents and children, grandparents and grandchildren, or aunts or uncles with nephews or nieces.
If first cousins have children, the children are second cousins to each other. They're the same generation as each other, because they share a set of great-grandparents. If second cousins have children, the children are third cousins to each other.
According to experts, cousins are sexually attracted to each other because blood relatives are raised in the same environment. They become so familiar with each other that even if they appreciate one another's physical appearance, there is a feeling of repulsion if they think about having a sexual relationship.
blood relative. A person who is related by birth, rather than by marriage, including those of half-blood. A blood relative includes a parent, brother, sister, aunt, uncle, nephew, niece, first cousin, or any of the aforementioned prefixed by "grand", "great-grand", or "great-great-grand."
Contrary to widely held beliefs and longstanding taboos in America, first cousins can have children together without a great risk of birth defects or genetic disease, scientists are reporting today. They say there is no biological reason to discourage cousins from marrying.
What is considered inbred family?
Inbreeding refers to the mating of close relatives in species that are normally outbreeding. Matings between father and daughter, brother and sister, or first cousins are examples of inbreeding. Many species of plants and animals have evolved devices to minimize close inbreeding.
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Following are some of the most common cousin marriage side effects:
- Genetic Diseases.
- Hearing Loss.
- Eye Diseases.
- Neonatal Diabetes.
- Limb Malformation.
- Schizophrenia.
- Blindness.
- Disorder of Sex Development.

References
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