Cousins Removed

Two or more persons sharing parents are siblings. Two or more persons with the same grandparents are cousins or first cousins or conversely two or more grandchildren are first cousins. Therefore, two or more great grandchildren are second cousins, two or more great great grandchildren are third cousins, and so on.

Rule One: Cousins in the same generation are simply cousins. If they share the same grandparents, they are cousins or first cousins. If they share the same great grandparents, they are second cousins. If they share the same great x2 grandparents, they are third cousins, etc.

Rule Two: Cousins of different generations are cousins removed. One generation apart is once removed. Two generations apart is twice removed. Three generations is three times removed, etc.

Now the problem is to reconcile the two rules. The secret is to remember that the earlier cousin (i.e. earlier generation) takes precedence.

What is the relationship between a great grandchild and a great x3 grandchild? The great grandchild takes precedence, being the earlier generation. Being a great grandchild means they share great grandparents. That makes them second cousins. Being two generations apart makes them twice removed. They are second cousins twice removed.

Work in reverse. Start with two first cousins three times removed and come up with their relationship to the common grandparents. If they are first cousins, they must share the same grandparents. If they are three times removed, they are three generations apart. That makes the earlier cousin a grandchild and the other a great x3 grandchild.

Test your skill. (1) In your family tree you have two third cousins four times removed. What relationship does each cousin have to the common grandparents? (2) In your family tree you have grandparents with one great grandchild and one great x5 grandchild. What is the relationship between the two grandchildren? Answers--but don't cheat, try first then look.