Q. I have heard the expression “second cousin once removed” or “twice removed.” What exactly does this mean?
A. All cousins share a common ancestor. Your “degree of cousinhood” (second, third, fourth) depends on how many generations back that common ancestor is. Take your first cousins, who you know are your aunts’ and uncles’ children. You all have the same grandparents. Your second cousins share a set of great-grandparents with you, your third cousins have the same great-great grandparents, and so forth. So your granddaughter and your sister’s grandson would be second cousins, for example they have two generations between them and the common ancestor (your parents).
“Removes” enter the picture when two relatives don’t have the same number of generations between them and their common ancestor. One generation difference equals one remove. Let’s go back to the previous example say your granddaughter has a son. He has three generations between him and the common ancestor (your parents), but your sister’s grandson still has only two generations in-between. So they would be second cousins, but once removed. Likewise, your grandparents’ cousins are your first cousins twice removed because of the two-generation difference from you to your grandparents. Your great-great-grandparents are still the common ancestor.
Still confused? You can use the relationship chart below to easily sort everyone out. First identify the common ancestor. Then find both relatives’ relationship to that ancestor on the sides of the chart. Where the row and column meet you’ll find their relationship.
You can read more about relationships in Dozens of Cousins by Lois Horowitz (Ten Speed Press) and Kinship: It’s All Relative, 2nd edition, by Jackie Smith Arnold (Genealogical Publishing Co.).
|CHILD||GRANDCHILD||THIRD GREAT-GRANDCHILD||GREAT-GREAT-GRANDCHILD||GREAT-GRANDCHILD||COMMON ANCESTOR|
|grandnephew or niece||great-grandnephew or niece||great-great-grandnephew or niece||CHILD||nephew or niece||siblings|
|first cousins three times removed||nephew or niece||first cousins||first cousins twice removed||GRANDCHILD||first cousins once removed|
|grandnephew or niece||second cousins once removed||first cousins once removed||GREAT-GRANDCHILD||second cousins twice removed||second cousins|
|second cousins once removed||great-grandnephew or niece||GREAT-GREAT-GRANDCHILD||first cousins twice removed||third cousins||third cousins once removed|
|THIRD GREAT-GRANDCHILD||third cousins once removed||fourth cousins||great-great-grandnephew or niece||second cousins twice removed||first cousins three times removed|