Cousin calculation

zmgakt7uw2dvfs

My double first cousin recently had a baby. I also had a baby this year. What is the relation between:

1. Our children (they share four great grandparents)
2. Me and the child of my double first cousin

Thanks!

pinkypinky

Your children are second cousins, double, if you like.

Your cousin's child is still your first cousin once removed.

feargale

1. They are both one and the same person.

pedroeibar1

feargale wrote: »

1. They are both one and the same person.

You cannot be your own cousin, double or other. First-cousins share two grandparents but no parents, and second-cousins share two great-grandparents. Double first cousins means that both sets of grandparents married brothers and sisters – i.e. a brother-and-sister pair had married with a sister-and-brother pair.
Children of first-cousins are second-cousins, and children of second-cousins are third-cousins, and so on. ‘Removed’ means a generational gap/step, (too often misunderstood as relating to marriage).
Pinky is correct, and you need to study your 'relatedness coefficients'.

spurious

This may help:
Family-Relationship-Chart.jpg

KildareFan

Ok - I'm taking OP to mean by double cousins that two siblings married another pair of siblings. This happened in my mother's family. Her brother Ike married Tina and had a son called Rufus, and my mother's sister Kim married Tina's brother Kanye and had a daughter called Easter [names changed to protect the innocent], so Rufus and Easter are first cousins on both their mother's and their father's side - is this what OP means by double first cousins? It also meant that Ike's sister was also his own sister in law, and Tina's brother Kanye was also her brother in law...

To simplify:
Ike + Kim = brother & sister
Tina + Kanye = sister & brother
Ike + Tina + Rufus = father + mother + son
Kanye + Kim + Easter = father + mother + daughter
Kanye + Kim + Rufus = Uncle + Aunt + Nephew
Ike + Tina + Easter = Uncle + Aunt + Niece
Rufus + Easter = 1st cousins

Assuming Rufus and Easter don't marry each other (which would totally mess up the gene pool) and go on to have children, then:
Rufus + Easter's children = 1st cousins once removed
Easter + Rufus's children = 1st cousins once removed
Easter's children + Rufus's children = 2nd Cousins

To simplify even further:
"I'm My Own Grandpa"

Now, many many years ago
When I was twenty three
I was married to a widow
Who was pretty as could be

This widow had a grown-up daughter
Had hair of red
My father fell in love with her
And soon the two were wed

This made my dad my son-in-law
And changed my very life
My daughter was my mother
'Cause she was my father's wife

To complicate the matters
Even though it brought me joy
I soon became the father
Of a bouncing baby boy

My little baby then became
A brother-in-law to dad
And so became my uncle
Though it made me very sad

For if he was my uncle
That also made him the brother
Of the widow's grown-up daughter
Who, of course, was my step-mother

I'm my own grandpa
I'm my own grandpa
It sounds funny I know
But it really is so
I'm my own grandpa

My father's wife then had a son
That kept them on the run
And he became my grandchild
For he was my daughter's son

My wife is now my mother's mother
And it makes me blue
Because, she is my wife
She's my grandmother too

I'm my own grandpa
I'm my own grandpa
It sounds funny I know
But it really is so
I'm my own grandpa

Now, if my wife is my grandmother
Then, I am her grandchild
And every time I think of it
It nearly drives me wild

For now I have become
The strangest case you ever saw
As the husband of my grandmother
I am my own grandpa

I'm my own grandpa
I'm my own grandpa
It sounds funny I know
But it really is so
I'm my own grandpa

I'm my own grandpa
I'm my own grandpa
It sounds funny I know
But it really is so
I'm my own grandpa

pinkypinky

I can't believe I'm allowing this thread to continue....

Double first cousins are when the parents of each cousin are 2 sets of siblings.
The children of any type of first cousins are second cousins. They share a set of great-grandparents. You always take one away from the ordinal number to get the common ancestor. 2nd cousins (2-1=1) great-grandparents.

Kildarefan: I don't know who Norah is in your scenario above because she pops out of nowhere.

It is a very common misconception in Ireland that second cousins are 1st cousins once removed. If I see anyone espousing that view, I'm editing their post!

zmgakt7uw2dvfs

Yes in my case my father and his brother married two sisters from an entirely separate family. I thought the definition of double first cousin was well understood. It seems not.

RobertKK

My father has double first cousins.

My second cousins.
Mod note: this is not correct. Your father's first cousins, of any variety, are you first cousins once removed, as are your own cousins' children.

Earnest

RobertKK wrote: »

My father has double first cousins.

My second cousins.

Your father's double first cousins are your double first cousins once removed. Their children are your second cousins.

pedroeibar1

Brayson Thoughtless Neckerchief wrote: »

.............. I thought the definition of double first cousin was well understood. It seems not.

Ten posts so far and eight fully understand it.

VirginiaB

That's 80%--much higher than the understanding of cousinship among most people I know.

pedroeibar1

VirginiaB wrote: »

That's 80%--much higher than the understanding of cousinship among most people I know.

Indeed, but this is a genealogy forum so it is highly likely that the regular posters would know the relationship exactly. Random people would not be as knowledgeable, as alluded to by several.

pinkypinky

We're starting to repeat ourselves now. I'm closing the thread.