On Cousins

Due to the recent additions to the extended family, I got curious and studied up on the whole naming convention surrounding cousins...

Apparently, the first/second/third thing is defined by the minimum number of generations separating one of the two people in question from their nearest common ancestor, while the "once removed / twice removed" thing is the difference in generation between the two people in question.

Easier explained by example (actually, easiest explained by the chart in the above-linked article!)

So, TwinGirl & TwinBoy and TwinCousin (my newly arrived nephew) are one generation away from their nearest common ancestor (TwinMamaw & TwinPapaw), so that makes them, naturally, first cousins. There's no "removed" because they are all of the same generation. However, assume for a moment, some time in the future, TwinGirl has a child named Fred. Fred and TwinCousin would be "first cousins, once removed" because again the common ancestor is TwinMamaw, one generation from TwinCousin ("first cousins"), but TwinCousin and Fred are a generation apart ("once removed"). Now, if TwinCousin has a child, named Mary, Fred and Mary would be second cousins because you have to go two generations back to a common ancestor, but not removed because they're both the same generation. However, Mary and TwinGirl would be first cousins once removed for the same reason Fred and TwinCousin are.

Now, let's look at a more complicated example.

Starting with TwinGreatGrandpa, there's TwinGrandpa, then me, then TwinBoy. Also, there's Uncle DH (who married TwinGrandpa's sister), Cousin DH (his son), Cousin JH (his son) and then cousin BH (his daughter).

Cousin DH and I are first cousins, JH and I are first cousins, once removed, and BH and I are first cousins, twice removed. Cousin DH and TwinBoy are first cousins, once removed, JH and TwinBoy are second cousins, and BH and TwinBoy are second cousins, once removed.

So basically, I am first cousins (+/- some removes) with every descendant of TwinGreatGrandpa because I am one generation away from the "start of the tree". My kids are first cousins once removed with TwinGreatGrandpa's grandchildren (because those grandchildren are one generation away), but second cousins (+/- some removes) with his great-grandchildren and their descendants (because the nearest person is two generations away from the common ancestor).

Confusing? Yes, but not so bad once you grok the pattern.

Welcome to the family, TwinCousin!!