It's All Relative

Over the Christmas holidays, I was home visiting with lots of family members and the subject of “first cousins, once removed” and “second cousins” came up.

Having attended a Catholic seminary and having to know who-and-who-cannot get married in the church, I arose as the expert.

Actually, I know everything, but my friends and family keep forgetting this.

So, here’s how it works.

My first cousin is Patrick. His kids are my “first cousins, once removed.”

First cousins, once removed, are always one generation apart.

If I had kids, then my kids and Patrick’s kids would be “second cousins.”

(All of their kids would be third cousins).

Second cousins are always of the same generation.

Patrick’s grandchildren would be my first cousins, twice removed.

Double First Cousins

Let’s say my brother and I married two sisters from another family. All of our kids would be “double first cousins.” Genetically, double first cousins are the same relation as half-siblings.

Legally, one cannot marry one’s double first cousin.

The children of double first cousins (double second cousins) cannot get married either because they are related just as closely as first cousins.

My paternal grandmother had double first cousins. It happened more frequently back in the old days when more folks lived on isolated farms.

Siblings from one farm would pair up with siblings from the neighboring farm. After all, who else would have been available?

If two identical twins marry two other identical twins, then their children are double first cousins but are genetically related just as closely as brothers and sisters.

They certainly can’t get married.
Their kids would be squash.

I once knew of a guy who found out that he was pretty closely related to his wife after they’d had three kids.

It turns out that his grandfather had had an affair with the neighbor. This guy married the daughter of this neighbor – the child that resulted from his grandpa’s illicit tryst. He didn’t know that his wife was actually his “half-aunt” until after they’d had three children.

(Cue up banjos playing in background. . . )