Can Second Cousins Marry Each Other? | Genetics Ancestry

Second Cousin

The possibilities in meaning of Second Cousin are endless. With each generation, the number of cousin hoods is doubled from one generation to the other. For example, when you decide to arithmetically count back 10 generations, what you will get in terms of numbers is a massive 2,046 ancestors which shows that the second cousin likelihood is huge. If you go through the statistics, it is possible to have millions of them!

Second Cousin

What Makes You a Second Cousin?

The simple fact that you shared ancestry with a person makes you a second cousin to that person. However, there is some complexity in it that you must understand in other to fully define second cousin’s meaning. The direct line of this cousin is only limited to your ancestors which include parents, grandparents, great-grandparents, and the like. The siblings of your ancestors are your uncles and aunts and not your cousin. There are degrees of cousin hood that are categorized into first, second, third, fourth, and so on; to make things out, you must make out the ancestor that you share with your cousin and the number of generations that separate you from each other. Let us take a look at some definitions in this regard:

  • First cousin – We shall take a look at the second cousin crossword clue and use it to define the first cousin. The first cousin is referred to as full cousin and is the child of your uncle or aunt. Your most recent ancestor that you share with your first cousin is your grandparents. You will share roughly 12.5% of your second cousin’s DNA percentage. 
  • Second cousin – The children of your parent’s first cousins can be referred to this cousin under review. When you take a look at the family tree of your ancestors, it will be seen clearly that you and this category of cousin have the same grandparents. In this regard, you will share 3.125 percent of your second cousin’s DNA percentage
  • Third cousin – Your third cousin is determined by your great-great-grandparents are the indices used in the measurement. I hope you get the picture clear here.

The Cousin Removes

If we must calculate the cousin removed, we have to understand the term. Now, what is cousin removed and why is it called second cousin once removed marriages? In a situation where two relatives do not have the same number of generations between them and traces of their most common ancestor are not known, the term removed comes into the picture. When we have one generation difference, it equals one remove. If your granddaughter has a son, there are three generations between him and your parents (your common ancestor) and in the case of your sister’s grandson, there are only two generations that stand in-between. This will present the scenario of second cousins but once removed. When we look at it through the lens of our great-great-grandparents, we will have common ancestors. 

The comprehension of one’s family tree is genuinely captivating and plays a crucial role in establishing connections across generations. If you’re inquisitive about the relationship between my great uncle’s son and me, Genetics Ancestry possesses the answer.

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Figuring Out What Type of Cousin You Are

It is fun locating and connecting with your relationship that is separated by hundreds and even up to thousands of years. When you are dating a second cousin and you know about your family tree, it will help in building a stronger relationship between you.  We shall take a look at how you can figure out the type of cousins you are with anyone that is your close relative in the following steps:

What is the Most Recent Ancestor

Starting from a specific person in the family tree, first identifies your most recent ancestor. 

The Relationship of each Person

Next, you must find out the relationship of each person under scrutiny to your ancestors. The nature of the most recent ancestor that you shared with any person will determine the type of bond in cousin-ship that you shared with the person. The second ones that we are reviewing here are those that share the same grandparents. We go on to the third, fourth, and so on. 

Genetics Ancestry Fact: Double cousin DNA percentage share double the percentage of DNA seen in first cousins.

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Equalizing the Cousins

The target for easy equalizing of the cousins should be taken at the level of the one that is closest to your common ancestor. 

Differences in Generations

Things are more complex when we are talking about once removed. Each of the removals that happen signifies one generation of difference. When we are talking about second cousins once removed marriage; then understand that there is a generational gap that occurs within your family tree. 

What is Second Cousin

Can you Date your Second Cousin?

In answer to the topic question: can you date your second cousin; we can boldly say that there is no harm in you dating your second cousin. When we look at the story of Biblical ancestors, it can be seen that there are indecencies of marriage among their family tree. Can I marry my second cousin? The answer is yes! In a nutshell, there is no harm in dating someone that is your second cousin. Dating second cousins is legal going by the antecedents that we have in the records of the past. Other than this we have also covered some interesting facts about Double cousins in our article what are double first cousins?

Can Second Cousins Marry Each Other?

Yes, second cousins can marry each other in almost all jurisdictions around the world. There are generally no legal restrictions on marriage between second cousins.

Here’s a breakdown:

  • Legality: Marriages between second cousins are legal in all 50 states of the United States and most other countries. There are no close blood relations involved, so these marriages are not considered incestuous.

  • Genetics: The increased risk of genetic disorders in offspring is very low for second cousins compared to closer relatives like first cousins. The risk is generally considered statistically insignificant for healthy couples with no known family history of genetic conditions.

  • Cultural Factors: While legal, some cultures or religions may have social or religious beliefs that discourage marriage between even distant relatives. It’s always good to be aware of such factors if they might be relevant to your situation.

What is a Second Cousin Marriage Defect?

Though blood runs through the line in a family; the distance between the marriages of cousins is far enough and the chances of children getting through the marriage having defects are remote. What is a second cousin marriage defect? There is nothing much to write about in this because the chances of getting defective children are low. The arithmetic chances of getting babies with defects here are about 3.5%. 96 OR 97 out of every hundred babies are born without any major birth defect. 

The above are average estimates; people that are not related can give birth to children with defects and this will be determined by the composition of their DNA. In other to make assurances double sure if you are cousins, then you must see a genetic counselor that is trained expert in the understanding of the genes of people. You can find them around your area. 

Genes are Inherited from Your Parents

It should be stated here that the genes you carry are a direct result of what you inherit from your parents. There is a generational gap in cousins; therefore the risk of getting issues in second cousin marriage birth defects is a rare possibility. It is therefore safe to say that the chances of defects in marriage are very slim. The genes that your parents pass on to you are gotten from their parents; your grandparents get theirs from your great-great-grandparents. When it gets down to you after some generational gaps, there will be no issues relating to defects in any number of children sired by couples that are cousins.  

 Blood Relationship between Second Cousins

We are going to give a statistical answer through data analysis in answer to the question: are second cousins blood-related? Take a look at the table below:

Relationship Expected number of cousins Chances you can detect shared DNA (the likelihood of IBD)
First cousins 7.5 100%
Second cousins 38 100%
Third cousins 190 90%
Fourth cousins 940 46%
Fifth cousins 4,700 15%
Sixth cousins 23,000 4%


 It can be seen that the chances of sharing DNA and the likelihood of IBD in this category of cousins under review are at the highest peak possible – 100%. This test is very powerful and it shows that it shows more potent examples than what is seen through sibling DNA tests. The above table shows the expected number of cousins that each generation of cousins is expected to have. The estimates are based on 2-3 kids per generation. It is not a general rule so to say but gives a clear idea of how the numbers increase along the line of each family tree. This is one of the strongest tests to show that two people share a strong bond DNA in-between their lines. 

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Find an Obituary for a Specific Person 

The Theory Versus Reality

There are different theories aimed at determining how two different people share close relations. When this system is used, it can be discovered that you share 50% of your DNA with your parents and siblings. 25% is shared with your grandparents, nieces, nephews, and son on. The amount of DNA is expressed in centimorgans (cM). It is important to note that what would be considered a second cousin must share 3.125% percent DNA.

What is a second cosuin

Final Thought

The meaning of Second Cousin has been extensively discussed above. It is important to note that there are generational gaps between this cousin under review and the relationship that exists in their bloodline is determined by the genes that they have in common within them. You have been reliably informed that a relationship or marriage between them is legal; there are several biblical references that we can point to in this direction. There will be no cause for worry bothering on marriage defects when cousins in this category sire children. Defects are a function of genes and genes are shared between direct parents and the children that they give birth to. 

In the final analysis, what would be considered a second cousin has been extensively described above without leaving anything out. 


Can you explain the concept of “once removed” in relation to second cousins?

“Once removed” indicates a generational difference. For example, your parent’s second cousin is your second cousin once removed. The “removed” aspect signifies the difference in generations.

How might the study of genealogy help uncover the relationships between second cousins?

Genealogy involves tracing family lineages. By examining historical records, birth certificates, and family trees, one can determine shared ancestors and establish the connection between second cousins.

Could second cousins from different cultural backgrounds have unique kinship customs?

Yes. Different cultures have varying views on family relationships. This can influence the importance of second cousin connections and the customs surrounding interactions or gatherings.

In what scenarios might DNA testing be useful in confirming second cousin relationships?

DNA testing can verify second cousin relationships when traditional records are scarce. Shared segments of DNA between two individuals can provide strong evidence of a common ancestor and the degree of relatedness.

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