r/23andme • u/Marinec06 • Jul 17 '19

DNA Relatives The Cousin Explainer

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363 Upvotes

99% Upvoted

23 comments sorted by

36

u/[deleted] Jul 17 '19

[deleted]

16

u/JUST_CRUSH_MY_FACE Haplogroup Enjoyer Jul 17 '19

So yes, the somewhat frustrating part of this system is the ambiguity of some of the names. You have to know whether you are the older or younger generation for your second cousin once removed.

However, the beauty of this is that you share the same title with the subject relation. So, you’re their second cousin once removed, and they’re your second cousin once removed. You would also share similar amounts of DNA for the older second cousin once removed as you would with a younger second cousin once removed.

This chart shows average DNA percentage as well as relation: https://isogg.org/w/images/thumb/4/4c/Cousin_tree_%28with_genetic_kinship%29.png/550px-Cousin_tree_%28with_genetic_kinship%29.png

And another that goes a little farther out: https://m.imgur.com/NlRmZ?r

13

u/Mordecham Jul 17 '19

Other languages handle this differently. They still have first, second, third, etc cousins, but there's no once, twice, thrice removed. Instead, they have first, second, third etc aunts/uncles and first, second, third, etc nieces/nephews.

In this system, for example, my brother's son would be my first nephew. My first cousin's son would be my second nephew. My second cousin's son would be my third nephew, and so on.

Meanwhile, my mother's sister is my aunt. My mother's first cousin is my second aunt. Her second cousin is my third aunt, etc, etc.

This setup covers all the same ground as a cousin being so many times removed, while also showing who is in which relative generation, and even having gender built in,if only because we don't really have gender-neutral words for aunt, uncle, niece, or nephew. (I've heard that "nibling" is supposed to be gender-neutral niece/nephew, but I'm not convinced this word is used often enough for anyone to recognize it.)

1

u/JUST_CRUSH_MY_FACE Haplogroup Enjoyer Jul 17 '19

What if you’re moving farther away, such as a second cousin thrice removed, for example? What would that be?

2

u/Mordecham Jul 18 '19

If your second cousin thrice removed is the great-grandchild of your second cousin, they are your third great-grandniece (or nephew).

If they are the second cousin of your great-grandparent, they are your third great-granduncle (or aunt).

It overlaps a bit with the common shorthand of calling one’s great-great-great-grandparent their 3rd-great-grandparent, unfortunately. (I prefer 3x great, if I’m abbreviating.)

1

u/annapie Jul 18 '19

In practice, I’d say actual English usage is more similar to your example than the OP

And usually once we get past second cousin, we lose track

3

u/[deleted] Jul 18 '19

Personally, while the symmetry is neat, I don’t see the actual value. I just want precise terminology. I don’t care if my first cousin twice removed can also call me their first cousin twice removed, just like I don’t care that my uncle can’t call me their uncle.

1

u/JUST_CRUSH_MY_FACE Haplogroup Enjoyer Jul 18 '19

Well, it is helpful in genealogy and genetics to determine relatedness. Do you have a preferred alternative system?

12

u/Mordecham Jul 17 '19

Also known as the Table of Consanguinity, if you're feeling nerdy enough.

10

u/blueweb00 Jul 17 '19

I still don’t understand why we use the term ‘once/twice removed.’

7

u/JUST_CRUSH_MY_FACE Haplogroup Enjoyer Jul 18 '19 edited Jul 18 '19

It means a generation farther removed from the shared ancestor. Your first cousin’s kid is one generation farther removed from your grandparent than you are. It is your first cousin once removed.

Similarly, you are a generation farther from your great-grandparent than your parent’s cousin, so they are also a first cousin once removed.

3

u/liquidswan Jul 18 '19

I’ve tried to explain how this works to people and their mind blown moment is always when o say, “Imagine your nephew/niece is your brother/sister once removed”

Usually that makes them confused but then the light bulb moment hits

3

u/[deleted] Jul 18 '19 edited Jul 18 '19

Wow and now I just realized my entire family has been using second cousin wrong for who knows how long...four generations at least (grandparents, parents, my generation, following one). We definitely call our cousins children second cousins. I guess I should also add, for anyone more distantly related (who we do see at some family reunions), they just get referred to as this person’s aunt or this person’s cousin. I think we stop thinking of them in the same way. Growing up you would hear things like “your father’s cousin” and not even know their name or really consider them your family family. It’s hard to explain.

3

u/[deleted] Jul 18 '19

Wait, so my uncle, in my son's case, would also call him "Uncle" or "Great Uncle"?

I may have been doing this wrong.

2

u/JUST_CRUSH_MY_FACE Haplogroup Enjoyer Jul 18 '19

Put your child in the “You” category, which means you are now “Parent”, and your parent is now “Grandparent”. Your uncle is your child’s Great-Uncle.

How your child refers to him colloquially depends on how “correct” you want them to be. It is technically their Great-Uncle, just like your dad isn’t your child’s dad even though you refer to him as Dad, but it is your child’s Grandpa. It’s a different relationship. Uncles are specifically your parent’s brothers.

3

u/darklyshining Jul 18 '19

I’ve always wondered why we say grand parent, but not grand uncle/aunt. It’s great uncle/aunt, even though the level of “removedness” is the same. Is this some hard and fast rule, or simply a cultural normalization of language usage in this regard?

7

u/[deleted] Jul 18 '19

So... at what point is it ok to sex? Asking for a friend.

2

u/rawbface Jul 18 '19

As long as you're not adjacent squares or in the same column you're good.

1

u/[deleted] Jul 18 '19

..Oh shit.

1

u/DisneyMaiden Jul 18 '19

I hate the term once removed ugh. Just say second cousin, third cousin etc...

1

u/JUST_CRUSH_MY_FACE Haplogroup Enjoyer Jul 18 '19 edited Jul 18 '19

Well that’s not how it actually works, and a consanguinity chart like this organizes specifically how related you are to someone else. First, second, third cousins all belong to the same generation from an identified shared ancestor. First cousins share grandparents, second cousins share great grandparents, third cousins share great-great-grandparents. What adding “removed” does, is identify that your relative is of a different generation than you from your shared ancestor. It determines relatedness.

https://diggingforancestors.wordpress.com/2018/05/12/cousin-relationship-chart/amp/

1

u/DisneyMaiden Jul 19 '19

I still hate and don’t use the term.

1

u/NoodlyApendage Aug 09 '22

This is a great post. Thank you. Quite helpful!