Please explain 1st cousin, 2nd cousin, 3rd cousin and so on.

[maslex]

OK, I get that your first cousin is...

Your parent's sibling's children. But who would be your 2nd, 3rd, 4th, etc? And what does it mean, twice removed, etc?

 

[LittleMissMagic]

I was a little uncertain myself, so I looked it up.

From genealogy.com -

Cousin (a.k.a "first cousin")
Your first cousins are the people in your family who have two of the same grandparents as you. In other words, they are the children of your aunts and uncles.

Second Cousin
Your second cousins are the people in your family who have the same great-grandparents as you., but not the same grandparents.

Third, Fourth, and Fifth Cousins
Your third cousins have the same great-great-grandparents, fourth cousins have the same great-great-great-grandparents, and so on.

Removed
When the word "removed" is used to describe a relationship, it indicates that the two people are from different generations. You and your first cousins are in the same generation (two generations younger than your grandparents), so the word "removed" is not used to describe your relationship.

The words "once removed" mean that there is a difference of one generation. For example, your mother's first cousin is your first cousin, once removed. This is because your mother's first cousin is one generation younger than your grandparents and you are two generations younger than your grandparents. This one-generation difference equals "once removed."

Twice removed means that there is a two-generation difference. You are two generations younger than a first cousin of your grandmother, so you and your grandmother's first cousin are first cousins, twice removed.

 

[crashbb]

LittleMissMagic's explanation was pretty good.

A couple of additions (I work in genetic epidemiology, so spend a lot of time looking at family trees).

First, Second, Third, etc. is based on the your shared ancestors - first means you share grandparents, second means you share great-grandparents, etc.

As was posted, "removed" is when the two cousins are not in the same generation. I find it easier to think of it as when the two cousins do not have the same relationship to the shared ancestors. So, for example, the shared ancestors are the grandparents for one cousin and the great-grandparents for the other. These are first-cousins once-removed. You base the first/second/third bit on the cousin who is closest to the ancestors.

So....

Take the two people and figure out which ancestors they share and each persons relationship to the ancestors. For example, great-great-granparents. Based on this, you can determine first/second/third - in this case, third cousins.

If the relationships are different (e.g. great-great-granparents for one and great-grandparents for the other), choose the closest one (in this case great-grandparents) and choose the first/second/third (in this case second). Then, count the difference in the number of "greats" to determine how many removes (in this case, there is a difference of 1, so they are once removed). In my example, you end up with second-cousins once-removed.

Clear as mud?

A few common ones...

Your cousins' children are your first-cousins once-removed.
Your cousins' children and your children are second-cousins.
Your parents' cousins are your first-cousins once-removed.

 

[indimom]

LittleMissMagic got it.

But, I wanted to ask this?

Does anyone call 2nd and 3rd cousins your "shirt-tail cousins?"

Just wondering if that's common or regional?

 

[crashbb]

LittleMissMagic got it.

But, I wanted to ask this?

Does anyone call 2nd and 3rd cousins your "shirt-tail cousins?"

Just wondering if that's common or regional?

I've only heard "shirt tail" cousins to mean cousins that occur due to marriage (i.e. no blood) - the relationship is "riding on the shirt tails" of another relationship. I suppose it could be used for a really distant cousinship too (with the same idea of riding on the shirt tails). I've only heard a few people actually use the term.

 

[chiefmickeymouse]

LittleMissMagic's explanation was pretty good.

A couple of additions (I work in genetic epidemiology, so spend a lot of time looking at family trees).

First, Second, Third, etc. is based on the your shared ancestors - first means you share grandparents, second means you share great-grandparents, etc.

As was posted, "removed" is when the two cousins are not in the same generation. I find it easier to think of it as when the two cousins do not have the same relationship to the shared ancestors. So, for example, the shared ancestors are the grandparents for one cousin and the great-grandparents for the other. These are first-cousins once-removed. You base the first/second/third bit on the cousin who is closest to the ancestors.

So....

Take the two people and figure out which ancestors they share and each persons relationship to the ancestors. For example, great-great-granparents. Based on this, you can determine first/second/third - in this case, third cousins.

If the relationships are different (e.g. great-great-granparents for one and great-grandparents for the other), choose the closest one (in this case great-grandparents) and choose the first/second/third (in this case second). Then, count the difference in the number of "greats" to determine how many removes (in this case, there is a difference of 1, so they are once removed). In my example, you end up with second-cousins once-removed.

Clear as mud?

A few common ones...

Your cousins' children are your first-cousins once-removed.
Your cousins' children and your children are second-cousins.
Your parents' cousins are your first-cousins once-removed.

Thanks for the info. I have been doing this wrong my whole life.

 

[PollyannaMom]

This thread is really helpful! I get the labels but have had trouble explaining them before.

I have heard the term "shirt-tail relations" used to mean distant cousins, etc.

 

[manning]

I once went over this with someone and my eyes glazed over. Just give me a flow chart.

 

[Grandmouse]

A little off topic here, but then there is the "grandaunt/greataunt debate (or uncle as the case may be). I know people who call themselves "great aunt or uncle" when referring to the child of their niece or nephew. When you are the same generation as the grandparent, you are a grandaunt or uncle, not a "great" unless you are the same generation as the great-grandparent.

 

[timmac]

Here's a formula, for those that prefer it that way:

Consider two people in a family, and find their common ancestor. Call A and B the number of generations between each person and this ancestor.

Then:

MIN(A, B) - 1 is the type of cousin you are.

ABS(A - B) is how many times removed.