Do you want to learn about sixth cousins? In this article, find out what a sixth cousin is, how they are related, how many you have, and more!
Cousin relationships can be confusing and hard to keep track of, and sixth cousins are no exception. In fact, they might even be more confusing than other types of cousins because they are more distantly related to us.
It is most unlikely that you grew up knowing any of your sixth cousins. However, if your ancestors have lived in the same geographic area for many generations, you might have met a sixth cousin while walking down the street and have not even known it.
Most people become curious about these more distant cousins through family tree research, or even DNA testing. DNA results often come with a list of genetic relatives, and we might discover that some of these relatives are sixth cousins.
What is the definition of a sixth cousin?
Sixth cousins share great-great-great-great-great grandparents, and are descended from different children of those ancestors. Another way to put it is that your great-great-great-great grandparent and the great-great-great-great grandparent of your sixth cousin were siblings.
Sixth cousin is often written as “6th cousin”, or abbreviated like this:
If you and your cousin are both descended from the same child of those 5th great-grandparents, then you might be fifth cousins instead of sixth cousins.
Are sixth cousins distant cousins?
Sixth cousins are distant cousins. In fact, most people would agree that sixth cousins are even very distantly related cousins.
The main reason that we call sixth cousins distant relatives is because of the sheer number of sixth cousins that we likely have and the degree of separation between us. Since we have 128 great-great-great-great-great grandparents (the common ancestor shared with 6th cousins), sixth cousins are simply less notable in our family tree.
How many degrees of separation are there between sixth cousins?
Sixth cousins are separated by 14 degrees consanguinity. We calculate this by counting up seven degrees to the most recent common ancestor (5th great-grandparents) and then down seven degrees to our sixth cousin, for a total of fourteen.
If you consider that parents are only one degree of separation from us, and first cousins are four degrees away, we can better understand why sixth cousins are considered to be very distant relations.
What is a sixth cousin once-removed?
A sixth cousin once-removed is the child of your sixth cousin, or the parent of your seventh cousin. The common ancestor shared between sixth cousins once-removed is still the 5th great-grandparents of the person who is in the generation most recently descended from the shared ancestor.
We often see sixth cousins once-removed abbreviated like this:
We say that a cousin is once-removed when they are not on the same generation as we are. In the case of 6th cousins, we would say one is once-removed when they are a generation away from us.
The children of sixth cousins are seventh cousins.
What is a half-sixth cousin?
While many sixth cousins share two 5th great-grandparents, some might share only one. We call a half-sixth cousin someone who shares only a single great-great-great-great-great grandparent with us.
Half-relationships are very common in cousins, since it was as common historically as it is now for a person to be married more than once during the course of their life. If a person remarried, children born in the second marriage were half-siblings to those born in the first.
The great-great-great-great grandchildren of those half-siblings will be half-sixth cousins/
How many sixth cousins do you have?
While you might be shocked to hear it, you could have as many as 17,300 sixth cousins. That’s enough 6th cousins to fill a sports arena!
If your family was particularly excellent at procreation and was touched by fortune and good circumstances, you might have even more. Of course, the exact number of sixth cousins that you have will depend on many factors.
How to find your sixth cousins
The fastest way to locate sixth cousins, who can be very helpful as partners in genealogy research, is to take a DNA test. Ancestry DNA has the largest database of customers, and many of them are also interested in building their family trees and connecting with distant relatives.
Do you share DNA with sixth cousins?
While we might have tens of thousands of sixth cousins, we won’t share DNA with all of them. We might share DNA with less than 2% of our 6th cousins, which means that if 17,300 of our 6th cousins took a DNA test, we might show up as distant genetic matches to only about 346 of them.
Even so, a few hundred 6th cousins on a DNA match list is plenty for most of us to research and connect with.
Those 6th cousins who do share DNA with us will likely share only a small amount. For example, according to data collected for the Shared cM Project, most sixth cousins shared between 10-50 centimorgans (cM).
I hope that you have found all of the information about sixth cousins that you were looking for in this post. If you have any questions about something that you read here, or if you have ever met one of your sixth cousins in person, I would love for you to leave a comment in the discussion below.
Thanks for reading today!