New from the "You're Kidding, Right?" department, we find out that it's significant that Donald Trump and Hillary Clinton are distant cousins.
Genealogists have apparently figured out that Trump and Clinton both descend from English King Edward III, making them 19th cousins, give or take a once-removed. Trump traces his descent through his mother's family (the MacLeods), and Clinton through her father's (the Rodhams).
Author A. J. Jacobs, who worked with genealogical research website Geni.com to figure all this out, waxed rhapsodic about what it all meant.
"Their 18th great grandfather is King Edward III, so there is precedent for ruling a country," Jacobs said. "It’s in their genes."
Turns out, according to the article, that not only do Clinton and Trump have British royal blood -- so does every one of the United States presidents except for Martin van Buren (mostly because van Buren was of Dutch ancestry). All of the others, apparently, descend from King John of England, not that that's any great claim to fame, as John was so notorious for losing territory through military ineptitude that he was nicknamed John "Lackland," and has been described by historians as "petty, spiteful, and cruel."
Be that as it may, there are a couple of problems with this whole contention.
The first one is the idea that being 19th cousins would confer upon a pair of people any related traits at all. Let's suppose that such characteristics as "fitness to rule a country" are actually inheritable -- a supposition, by the way, which is almost certainly wrong, but which for the sake of argument we'll bear with for the time being. How many of Edward III's kingliness genes would Clinton and Trump share?
Assuming that Clinton and Trump have no other common ancestry -- another lousy assumption, as you'll see in a moment -- to figure out the proportion of their shared heritage, you'd use something like the following calculation. Siblings have the same parents; first cousins share one set of grandparents, and therefore half of their lineage; second cousins, one set of great-grandparents, and thus a fourth of their lineage, and so on. So the shared heritage of a set of nth-degree cousins is 1 over 2 to the nth power. Which in the case of 19th cousins, means that...
One-524,288th of their ancestry is the same. In other words: not much.
But what about that assumption of no other shared ancestry? The number of ancestors in your family tree doubles every generation; so it's the inverse of the previous calculation. If there have been 19 generations between Edward III's time and now, then Trump and Clinton would each have something over five hundred thousand ancestors. Each.
Given that current estimates of England's population in the mid-14th century average at around four million individuals, what's the likelihood that they don't descend from damn near every medieval British person who left descendants -- kings, commoners, peasants, all of them? Everyone with English ancestry is related, and the chances are good that they all descend from royalty.
Oh, and while we're on the subject: my wife also descends from King Edward III. I don't seem to, although on the Scottish side of my family I descend from King Duncan (of Macbeth fame) through my ancestor Alexander Lindsay, the evil "Red Earl" who lost his soul to the devil in a dice game and now haunts Glamis Castle, swearing loudly and scaring small children.
So maybe there's something to this genetic predisposition thing, after all.
It's kind of funny that this sort of claim gets circulated at all, given the fact that with a little bit of logic and a few simple calculations, you can easily see how ridiculous it is. Maybe it's because the whole concept of royal blood and nobility has been so drilled into our cultural consciousness by fairy tales that we think it must mean something if you can trace your ancestry back to King Angus the Demented. Or maybe it's because a lot of people can't be bothered to question what they read.
Myself, I'm just as happy that the majority of my heritage (with the exception of the aforementioned evil Earl) is solid peasant stock. Some of those kings and queens were loons.