What is a Sixth Cousin?

Are you interested to know what a sixth cousin is and whether you are genetically related to them? In this article, we'll help you understand what a sixth cousin is, whether they are considered family, and what DNA results might say.

In the world of cousin relationships, it’s often the closer the better when it comes to understanding just how you are related. First cousins, for example, are the children of your aunt or uncle and in some families, these cousins are your earliest friends in life.

When we get to second cousins it becomes a little more complicated because these cousins are the grandchildren of a sibling of your grandparent. Basically, they are your great aunt or uncle's grandchild. It goes on like this each generation with the number level of the cousin increasing.

It gets really complicated, however, once we reach the sixth generation of separation in the form of sixth cousins. Just how are they related to us?

What Is a Sixth Cousin?

Just like any cousin relationship a sixth cousin shares a common set of ancestors with you. In this case, your mutual great-great-great-great-great grandparents are these shared ancestors. The children of these common ancestors were siblings and respectively yours and your sixth cousin's great-great-great-great grandparent.

In order to understand this relationship a little better, it is important to note that the number of generations between you and your mutual ancestor is the same as the cousin level. So there are six generations between you and your cousins' great-great-great-great-great grandparents. Therefore, you are sixth cousins.

Are Sixth Cousins Blood Relatives?

When you stop to consider this distant cousin relationship it is important to note that to reach you and your sixth cousin's generation there are about ten marriages into the family from non-blood relatives. Only one person in each of these marriages carries the blood of your mutual ancestors so there is a great deal of separation between you and your sixth cousin.

In terms of a family connection, it is highly unlikely that you would meet or knowingly encounter a sixth cousin. Even at a huge family reunion the odds of a sixth cousin being in attendance are small. Society, in general, is not that tight.

The distance socially is matched in our blood as well. The further we get away from our common ancestors the less DNA we share with our cousins. In a perfect world, the DNA we share with a cousin would half with each generation meaning on average we might share 0.025% of our DNA with a sixth cousin.

With such a low expected amount of shared DNA and the realistic nature of recombination we actually share little to no DNA with the vast majority of our sixth cousins. So when you factor all those sixth cousin matches on AncestryDNA or 23andMe there are likely thousands who have either not tested or share no DNA with us.

How Many Sixth Cousins Do We Have?

If you were considering the possibility of tracing all of your sixth cousins this next statistic may make you think again. It is estimated that we could have up to 174,000 sixth cousins which may seem astronomical and impossible to track.

What we must remember is that we have 128 sets of great-great-great-great-great grandparents. The number of offspring from each successive generation grows exponentially and we are the seventh generation from our common ancestors.

Any sixth cousin matches we have from our DNA test are a tiny proportion of the actual sixth cousins. That said, if we still live in the same general area that our great-great-great-great-great grandparents did, it is highly likely we encounter sixth cousins daily and have no idea.

Variations on the Sixth Cousin

There are some other terms that can be applied to fifth cousins which denote a slight difference in the actual relationship.

• Sixth cousin once removed: The sixth cousin once removed could either be the child of your sixth cousin or your relationship to your parents' sixth cousin. The removed aspect refers to a separation by one generation.
• Sixth cousin twice removed: If you are considered twice removed this would mean the person was either the grandchild of your sixth cousin or the sixth cousin of your grandparent. Again, the removed term applies due to two generations of separation.
• Half sixth Cousins: A half sixth cousin is still in the same generation as you are but your respective great-great-great-great grandparents were only half siblings. This half sibling relationship makes each successive level of cousins only half cousins. The reason being they only share DNA with one great-great-great-great-great grandparent instead of both.

Conclusion

The sixth cousin relationship is considered a very distant one. We generally do not share a great deal of DNA if any at all with our sixth cousins but we do share common ancestors. Without those ancestors, neither of us would be here so in that we are at least connected.

Neil Edwards

Genealogist and family-tree research specialist

Neil was born in Shropshire, England surrounded by centuries of living history. His interest in the past has been a lifelong passion leading to undergraduate degrees in both Economic History & Geography and History & Politics.

This interest in history quickly translated to family history when he moved to the U.S. in 2010. It was here that he began working on his own family tree as well as that of his American wife. That research allowed him to gain a wealth of experience working with both U.S. and European genealogical documents and studying their best uses in researching family history.

Following 9 years of honing his genealogical research skills, Neil was proud to have earned a certificate in Genealogical Research from Boston University in late 2019. Neil also took part in the research process for a Duke University study into the families of 19th Century UK Members of Parliament.

Link To or Reference This Page

We spent a lot of time downloading, cleaning, merging, and formatting the data that is shown on the site.

If you found the data or information on this page useful in your research, please use the tool below to properly cite or reference Name Census as the source. We appreciate your support!