The meaning of cousins ‘removed’

Recently we had as dinner guests a colleague and his wife and during the evening he happened to mention that someone was “his first cousin once removed’. I seized on this because I had never been sure what that meant and so asked him. He said that when he talked about someone being his first cousin once removed, he meant someone who was a child of his first cousin. But when I asked him how that other person would refer to him (since he was not the child of that person’s first cousin) he said he was not sure. I have also heard some people refer to the child of a first cousin as a second cousin.

The invaluable Wikipedia says that there is a logical system. The generic term ‘cousin’ refers to any family relationship where two people share common ancestors without one being an ancestor of the other.

The meanings of the more specific terms are straightforward when two people have the same number of generations to the common ancestors. ‘First cousins’ are the children of siblings. ‘Second cousins’ is how you refer to the children of first cousins (i.e., of the same generation). Third cousins refer to their respective children and so on. In every case, the number of generations separating them from their common ancestors is the same. ‘Cousins once removed’ means that there is a single generation difference between the two people, ‘cousins twice removed’ means that there is a two-generation difference, and so on.

It is quite logical but there still remains the original ambiguity that prompted this post. If you refer to your first cousin’s child as your ‘first cousin once removed’, should that person use the same term to refer to you or say that you are his ‘second cousin once removed’? In other words, is the primary referent number the smaller of the two possibilities or should it be the number of your parallel cousin? In either case, to really pin down the relationship, it seems like we need to specify if the ‘removal’ goes up a generation or down a generation.

This post may have been more helpful if I had done it before the holidays when families and friends get together and introductions require one to describe relationships.


  1. DonDueed says

    It seems to me that the specific relationship you describe would be something like “second cousin negative-once removed”, or “second cousin once added”.

    Seriously, though, I’ve never heard any specific terminology for it. Perhaps the convention is to use “first cousin once removed” in both cases when it applies to either party, but as you say it could be misleading if there’s no obvious difference in ages (or a reversed age difference from the expected one).

  2. Callinectes says

    Using the diagram I counted the steps up and then down to first cousin once removed (two up, three down) and then reversed it (three up, two down) to work out the reversed relationship. It seems that they are first cousins once removed both ways. The system is symmetrical, so it doesn’t actually tell you which direction the generation difference goes, only how much of a difference there is.

  3. jazzlet says

    Yup it’s the same both ways. The closest relatives I have on my mothers side are two third cousins and their children, my third cousins once removed, so as a family we worked this out because we needed to use it if we were to accurately describe the relationship.One of my nephews is good friends with one of my third cousins once removed so the social relationship is continuing despite the increasing distance in blood relationship.

  4. Bruce says

    While I believe the above comments are correct, I also think it doesn’t matter. If one has a family tree in front of everyone, then people can just point. If not, then numbers in sentences will be disregarded anyway. Why worry about perfect use of a code that few people know or use or care about? Most people have much closer connections to friends than to most of their cousins.

  5. jrkrideau says

    ‘first cousin once removed’ as others have said. I cannot even begin to grasp where the ‘second cousin once removed’ comes from in the above.

    It is also possible to have a first cousin twice removed, a second cousin once removed (not the same as mentioned above) and so on.

    @ DonDueed
    use “first cousin once removed” in both cases when it applies to either party, but as you say it could be misleading if there’s no obvious difference in ages (or a reversed age difference from the expected one).


    It is the relationship not the ages that are important here. I have first cousins once removed on my father’s side (that is my aunt’s grandchildren) who are older than I am.

  6. mynax says

    At a skeptic convention, I recall seeing shirts printed with a mosquito (or some other animals) and text like “My 30,000,000th cousin, 500,000,000 times removed”, which had to do with the most recent common ancestor between humans and mosquitoes, and the number of generations. Can’t find an image online.

  7. Steve Morrison says

    Frodo and Bilbo were both first cousins once removed and second cousins once removed, according to Gaffer Gamgee:

    ‘Well, so they say,’ said the Gaffer. ‘You see: Mr. Drogo, he married poor Miss Primula Brandybuck. She was our Mr. Bilbo’s first cousin on the mother’s side (her mother being the youngest of the Old Took’s daughters); and Mr. Drogo was his second cousin. So Mr. Frodo is his first and second cousin, once removed either way, as the saying is, if you follow me.[…]’

  8. Trickster Goddess says

    When I was a kid, I thought the adults were saying “first cousin once we moved.” Given that I had lived in 4 different towns by the time I was seven years old, I was confused as to how us packing up and moving house change our relationship to our relatives.

    I still can’t believe I didn’t figure it out until I was in my 20s..

  9. felicis says

    I think it depends on the family -- ours never bothered with such details -- if the relationship wasn’t ‘parent’, ‘child’, ‘aunt’, ‘uncle’, ‘niece’, or ‘nephew’ (or greats and grands) -- it was ‘cousin’ with no additional note. My great-aunt’s children were our cousins, as were their children. We didn’t bother keeping any closer track than that.

    Then again -- I have both a fairly small family and we were never terribly close.

  10. Mano Singham says

    Trickster Goddess,

    That is hilarious! But such childhood misconceptions that last into adulthood are not uncommon. This American Life had an entire segment where they talked to people about their misconceptions. I blogged about this and gave a link to the show which you might find amusing.

  11. derek lactin says

    I think my cousin’s daughter is my “first cousin once removed inferior” and I am that child’s “first cousin once removed superior”.

  12. Reginald Selkirk says

    Doesn’t matter, if they are that distantly related, I don’t feel obligated to buy them a gift.

  13. moarscienceplz says

    Step 1, find your common grandparent.
    Step 2, count the number of “greats” for each ancestral relationship.
    Step 3, take the smallest number and add 1, that is your degree of cousinhood.
    Step 4, subtract the smaller from the larger, that is your degree of removal.
    Example: If my grandmother is also your great great grandmother, the numbers are 0 and 2. Add 1 to 0 to get first cousins and subtract 0 from 2 to get twice removed.

    FDR and Teddy Roosevelt were 5th cousins. So, except for the odd occurence that the 10 people in the double chain of their relatedness happened to all be men, they would have had different surnames and almost nobody would have considered them to be related.

Leave a Reply

Your email address will not be published. Required fields are marked *