Alert readers may notice that in my second novel, The Strange Land, my main character’s love interest is also his cousin.

Ewww.

In my defense, I painted myself into a corner by writing about a small group of people who flee from a disaster in ancient history.  They are founders.  Some of them are going to have to marry their cousins.  By hypothesis, their genetic code is richer and less deteriorated than is ours today.  So cousin marriage is not going to have the same bad effects that we see today from years of inbreeding. 

Nowadays we have gotten rid of almost all of our sexual taboos.  But one we have kept is: don’t marry your cousin!  In the group I am writing about, it is almost the opposite.  They have a lot of common-sense taboos, but cousin-marriage is not one of them.

But wait.

Even they can’t marry just any cousin.

Let’s do some anthropology.

One thing anthropologists do when they are studying a culture is make a kinship chart.  This is like a family tree with, by convention, triangles representing males and circles representing females.  We make this kinship chart, we identify the Ego (the person whose relatives we are naming), and then we can discover and fill in words for all these relationships.  When I did this in Borneo, I discovered that the language I was studying had, for example, a unique word for the woman who is married to my husband’s brother.  (Duoi.)  Fun stuff.

As you might expect, different cultures have different ways to slice up the kinship universe and these ways tend to cluster with other cultural traits.  The chart I am about to show you is called the Iroquois kinship system, but it is also found in many other cultures around the world.  It tends to be found in cultures that have a patrilineal inheritance system.  My source for this is found here.  (I also found the chart there, but I re-copied it by hand to simplify it a bit and to avoid image copyright issues. If my handwriting makes your eyes bleed, I encourage you to follow the link and take a look at the original chart.)

As you can see, “Uncle” or “Aunt” means someone who is married to a relative of your parents’ generation, such as the man married to your mother’s sister.  There are unique words for “Father’s Sister” and “Mother’s Brother.” And – this is key – a parent’s sibling of the same sex is also considered your parent.

So, in the Iroquois kinship system you would call your mother’s sister “Mother.”  Her kids would be considered your brothers and sisters.  They are parallel cousins.  You do not get to marry them.  (You see, we still have marriage taboos, just not the same ones!)

On the other hand, the children of your mother’s brother are not called brothers and sisters.  They are called cousins. They are your cross cousins.  You are encouraged to marry them. The same is true for the children of your father’s sister.

This may seem strange to us, whose extended families are small and who have a wide world of non-relatives from which to select a spouse. But you can see that it would become important to anyone living in a small, isolated community.

Luckily for my character Ikash, the cousin on whom he gets a crush is the daughter of his father’s … sister. She is not just his cousin, she is his cross cousin. She is fair game, at least as far as the kinship system is concerned.  Of course, he still has to overcome her father’s grave doubts about him, but that’s another story …