On cousin marriage
Now the news is out that Graham Platner’s replacement, Troy Jackson, has a significant other (they’re not married) who is his second cousin and the mother of his two children:
Maine Democratic Senate candidate Troy Jackson is in a long-term relationship with his high school sweetheart — who is also his second cousin, according to a new report.
Jackson, 58, and Lana Pelletier share two adult sons and the same great-grandparents, according to Thursday’s report by independent journalist Steve Robinson, who notes that such relationships are both legal under state law and not uncommon in the rural North Maine Woods region, near the Canadian border.
While Jackson, a onetime logger and the former president of the Maine State Senate, has described Pelletier as his wife in the past, locals tell Robinson the couple has never been legally married.
Where to begin?
It used to be that people living in what used to quaintly be called “sin” – that is, in quasi-marriage outside of wedlock – were not especially politically viable. Those days are long gone, so that’s not the issue here. The issue is what I’d call the “ick factor” of being sexually involved with one’s second cousin.
But it’s not illegal anywhere in the US, nor is there much evidence that it’s harmful in the genetic sense unless there’s a known specific hereditary disease carried by both cousins. Here’s why:
he chance that a baby is born with a birth defect or disability is between 2-3%. So, if a hundred people have babies, we would expect that 2 or 3 to be born with some sort of problem. Which of course means that 97 or 98 are fine.
At 3.5%, the risk is slightly higher for second cousins. Still, 96 or 97 out of a hundred babies are born without any major problems.What this all means is that while there is increased risk, it doesn’t really qualify as a “high chance.” Even first cousins at 5% aren’t that big of a risk.
Keep in mind though that these are average numbers. Like people who are not related, your actual risk depends on the genes you and your spouse have.
Note that the article about Jackson mentions that such marriages are “not uncommon in the rural North Maine Woods region, near the Canadian border.” Well, it’s confession time: not only are such marriages “not uncommon” on the paternal side of my own family, but first cousin marriages were also “not uncommon” among that crew. In fact, they were very common.
And they didn’t live anywhere near the north of Maine, either. They lived in Belarus.
I didn’t know very much about my own heritage until I did some genealogical research on my family about seven years ago. I found out a great many fascinating things (see this for a previous post of mine on finding a long-lost maternal relation). One of those things was that my father’s family, even at the level of my grandfather’s generation – not one of whom I ever met, including my grandfather – tended to marry their first cousins. In fact, I found that the same three surnames occurred over and over and over, so much so that the families were intertwined in a way that made it difficult for my newly-found second cousins and I to determine just how closely we were related. Were we second cousins? Double second cousins? Double first-cousins once-removed?
We finally gave up on figuring it out, but got a great many chuckles about all of us being the product of some sort of vast network of first-cousin marriage. I finally figured out something about that, though: since the families were also very large (my paternal grandfather was one of between ten and sixteen children, the first born in the 1840s and my grandfather born in the late 1860s), and this was a typical family size back then, they probably had something like over a hundred first cousins.
That’s a mighty big pool from which to choose. If they lived in the same or neighboring villages and cities, it would be a pretty convenient pool, too. Why not marry a cousin and keep it in the family?
There didn’t seem to be a whole lot of insanity or any especially dramatic genetic diseases, as far as I can tell. Oddness yes, and eccentricity. But I’m not sure that wouldn’t have been the case even without the cousin marriage. There’s a marked tendency to be good at math, and that’s about it. We don’t look like each other, either. And below the level of my grandparents, I knew very few of these relatives, but found a whole host of them – really nice people, by the way – through genetic testing. We tried to piece together what had estranged the families, and decided it had to do with a business they were in together that precipitated a falling-out.
In recent years, there’s not been a whiff of cousin marriage or even second-cousin marriage in the group. But I guess that what I think of Jackson’s arrangement – I’m basically indifferent to it and certainly not especially shocked by it – has at least something to do with this family history of mine.
However, I can’t stand Jackson’s politics. But that’s a separate issue.

I know there are different ways of saying it, but Personally, I think if you have common great grandparents that would make you third cousins.
Second cousins would be one of your parents first cousins. ( In relation to you)
Hence, Example : my mom’s first cousin is my second cousin and his son my third cousin. That’s the way we figure it.
My paternal grandparents were ” second cousins” as people are calling this. Or ” third cousins” as our family called it. And that wasn’t the first time those two family lines – the Bakers and the Lees – had crossed. So they were more than just third cousins. I have always joked that I’m my own cousin on that side of the family.
There is a cute young girl who bartends at one the music clubs I frequent. There is a long history of fishermen families in my community, and they are predominantly Italian with some Portuguese that migrated here a century or so ago.
Chatting with the bartender, she said she’s Italian and she grew up here. Then she said that when she approached dating age, her parents told her. Whatever you do, don’t date any Italian boys! Why, I asked? They felt that the odds were high that he could be a first or second cousin. Ok.
It occurs to me, that there could also be the concern that the accepted lineage may not be the correct genetic lineage.
Jon Baker:
Nope.
First cousins are the children of siblings. Therefore, first cousins share one set of grandparents.
The children of first cousins are second cousins to each other. And their children would be 3rd cousins to each other.
“Once removed” is, on the other hand, crossing generations. For example, the first cousin of one of your parents would be your first cousin once removed.
A lot of people use the terms incorrectly, however.
Let’s bring in Einstein. He ended up married to Elsa Einstein, his first cousin on the maternal side and second cousin on the paternal side. No children, but still a bit odd. Cousin marriage wasn’t all that rare. Grok:
Estimates for British aristocracy/landed gentry in the 19th century were higher than the general population (roughly 3.5–4.5% first-cousin in some calculations by George Darwin). Second-cousin marriages were even less remarkable in these circles.
Second cousin marriage in villages could get as high as 10%-30% before modern transportation arrived.
I agree with Neo. I stand second to none in my loathing of Jackson’s politics, but a second cousin marriage is not scandalous or even noteworthy in the slightest. It would be a mistake to make this a campaign issue. Anyway, the parents of the great American geneticist Sewall Wright were first cousins, so you never know.
Re: Muslim cousin marriage…
Is allowed by the Quran and off the charts:
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Rates of cousin marriage in the Middle East have been found to vary from 29% in Egypt to nearly 58% in Saudi Arabia.
https://en.wikipedia.org/wiki/Cousin_marriage_in_the_Middle_East
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Even first cousins at 5% aren’t that big of a risk.
But when there is systematic inbreeding for generations, I’d guess that percentage goes up.
Another reason I see Islam declining.
Off-topic, but have you seen this article from Sasha Stone? Another example of a person who changed.
https://www.sashastone.com/p/did-i-just-leave-a-cult