The Theory of Eight Surnames

One, two, or many?

On a recent trip abroad, I was told that everyone should know and be able to recite their eight surnames. These are the surnames of a person’s eight great grandparents. A good game is to ask: can you name yours?

In Scotland, people can be expected to know just two ancestral surnames (their father’s and mother’s). With genealogy as a hobby, I know dozens of names, but to come up with The Eight… I had to think, then check. I am a bit ashamed how hard the challenge was/is. How lovely, to be able to just know your eight names like they were your own, and to produce them Trumpton-style! Because of course, they are your own. They are you, and you are them – none of us is just one link in a patrilineal chain.

Pugh, Pugh, Barney McGrew, Cuthbert, Dibble, Grubb!

Eight Surnames

Here we are then, for me and my siblings.

  • Black
  • Black
  • Laughland
  • Livingston
  • Mackinnon
  • McMillan
  • Scobbie
  • Stevenson

So I am not just a “Scobbie”. Not just one name, one line. Now I have eight barrels to my surname, on this approach.

“Why not sixteen?” I wondered. Well, my theory is that eight is manageable,* which is why it can become a convention, even though it has been an impossible challenge for everyone I’ve asked here at home, so far. We can all be pleasantly shamefaced to fail to know our eight! It’s not an impossible challenge. Then, once internalised, The Eight provide an overlaid identity and richer concept of self. And this doesn’t turn into boring or intimidating one-up-man-ship, which is what happens when scores of distant relatives are mentioned or the most ancient or famous ancestors get boasted about. I have a diverting answer to a question I am sometimes asked and don’t really want to answer, which is: “how far back have you got?”

The idea that because we have two parents, it makes us the combination of just two surnames… well, it is just as misleading as thinking we are merely at the end of a line of fathers. And given the popularity of DNA testing, it is now important to add that we are also not just a combination of two ancestral lines, a Y-DNA patrilineal one and a mitochondrial matrilineal one.

Being defined by the combination of just two lines of DNA? That’s as unreal as having just one surname. Indeed the very value of those specific lines is that they don’t change much and are shared by others. As whole people, we are the product of all our ancestors; and also of our families, our experiences, and our environment; in the expression and function of our DNA as well as in our psychology and looks.

Often in some specific respect we feel we are the doppelganger of someone specific, but it could be a 2nd cousin once removed, or great-great-aunt. You don’t need to share a surname.

Some numbers

As every genealogist realises pretty damn quick, the growth in direct ancestors, and their names, is exponential. Starting with our parents, the number of ancestors doubles with each generation. Five generations back, the list of your great-great-great grandparents can be expected to provide two to the power of five (32) different surnames. At that historical distance, your normal surname is mathematically and genetically a random choice in a sizeable lottery. Yet we get fixed with (and sometimes fixated on) just one.

To put a number on it, you are no more identified by your father’s surname than by any of the 31 others scattered through the 5th generation of your ancestors, except by our cultural norms. You are only 3% your surname. His surname. For most of us, a set of 32 surnames is not just a theoretical possibility, but true in practice, because it is relatively uncommon for cousins to marry or for coincidence to result in doublers. Some of us will have a slightly smaller set.

I have two unconnected Blacks… and I will return to them another time.

Well, it’s around 3% when you’re looking just five generations back. If you could go back 10 generations (around 250 years, which is not so far), your surname identifies on average 0.1%, or one thousandth, of your self, because two to the power of 10 is 1024. If Jeanie McGregor knows only that her 8x-great grandparent was Jimmy McGregor, that leaves 99.9% of Jimmy’s generation out of the picture. But the other 1,023 are equally her ancestor, even though she might proudly claim only “I’m a McGregor!”

So much more so for an ancestor 30 generations back (say, someone like King Robert the Bruce, 1272-1329). If he is an ancestor with only one path leading back to him through 30 generations, you would only get in theory only a billionth of your DNA from him. Of course, we are all inter-married like crazy in the real world… so the exponential maths needs to be replaced by something more realistic. But the point is, a famous ancestor is only one of many, most of them unknown, going back beyond the origin of our species. They are not very close relatives, those famous ones. Go far enough back and you’ll start thinking of pigs as being relatives as well as (or rather than) food.

And as it happens, my illustrative choice of “McGregor” was once an illegal surname, on pain of death! All surnames are not equal, and you might become very attached to a new one of your equal Eight. But it’s more distinctive to be attached to all of them.

Eight new surnames with every marriage

For most family historians, more ancestors keep appearing… recent ones. As soon as we take an interest in the ancestors of our spouse, or our child’s or sibling’s partner, we get 32 more 3xgreat grandparents to get interested in. Thirty two for each new family member! And then there are all the ancestors’ siblings, husbands, wives, children, cousins, 3rd cousins… plus the neighbours, employers, friends, work-mates, accidental namesakes and randoms who catch our interest. It’s a big job. It puts you in your place, which is not at the centre of the universe.

Eight names make a list just the right length for memory and recitation. If you are thinking of DNA, then it’s the generation where you get one eighth from each person, which is a manageable amount. 12.5%, or approximately 10%. We can get our head around that kind of proportion. It’s fair to each name, to each ancestor. It gives you eight historical paths to walk down.

I would love it if everyone had this knowledge of themself. I am actively trying to rote-learn mine by heart, right now. But in what order?Alphabetically? By birth date? Male-female? By couples? I’ve gone for alphabetical order because it’s random, and I can already easily remember who is married to who. Also, I have angry memories, as an “S” person, of always being at the end of every alphabetical list. Now I am a “B”. Hurray!

But anything goes.

In Scotland, naming all our ancestors for five generations is a reasonable aim, and not too hard for those of us lucky enough to have unusual names to deal with.

My wife’s eight-ish surnames are:

  • Coupar
  • Erskine
  • Hay
  • Inglis
  • Kinnis
  • McLaughlan
  • Spence
  • unknown

On the Family Tree page (link at the top) I will keep up-to-date ancestor tree diagrams for my eight names, and my wife’s eight names. I have a lot more information than this, in my database and online. But for now, it makes sense to group trees around our combined set of grand-parents. Each grandparent is one of the children of our eight, and I’ve included their siblings too, to make the trees more relevant for cousins and others.

These eight grandparents provide the names for our own children.

  • Black
  • Erskine
  • Hay
  • Kinnis
  • McKinnon
  • Scobbie
  • Spence
  • Stevenson

Eight surnames are so much better than just one.


Thanks to Leticia for telling me of this practice!

Since first writing, I’ve discovered there is a film called “Ocho Apellidos Bascos” (in Spanish) which means “eight Basque surnames” and is called Spanish Affair in its English-language release. It’s a culture-clash romcom and was Spain’s biggest domestic film in 2014 (and one of the biggest box office successes ever). It’s about a Spanish man who falls for a Basque woman. They pretend he is a “full-blood” Basque and the evidence for that is that he recites his eight surnames. The Basque lands are beautiful, the language (genetically unrelated to any other) is fascinating, and the politics are incendiary and sometimes deadly. Just to be clear, I think “variety” is no worse and no better than “purity”. We are who we are and none of us chose to be here. “We are all Jock Tamson’s bairns,” or, as the Burns song had it in 1795, “a man’s a man for aa that.” We are all equal.

Thanks to Eileen Lyon’s blog Myricopia of Aug 13 2019 titled The Shrinking Tree, I’ve learned the phrase “pedigree collapse”. See the Wikipedia entry, which estimates that everyone on the planet is a 50th cousin to everyone else, if not more closely-related.

If you find it useful to hear experts clearly and pleasantly debunk or unpack mathematical / statistical / numerical claims (usually ones in the news), listen to Tim Harford and colleagues on the BBC’s wonderful More or Less radio show. (It is available on the Word Service too.) There is a useful opinion piece on the topic here by another BBC regular, Adam Rutherford, here:

Paul Chiddicks @chiddickstree on Twitter posted this cracking exemplification of Pedigree Collapse: “Going back eight generations, most people will have a whopping 256, however, Charles II of Spain (1661–1700), was so inbred he had only 29 ancestors.” Nice!

And, as I learned on The Unbelievable Truth (Series 25, Episode 3, BBC Radio, 25 Jan 2021), “today, more than one in ten marriages are between first or second cousins… worldwide that is”. There are lots of cusbands out there! There are lots of references to this factoid on wikipedia, so maybe it’s true – but the maths is beyond me as to how this, repeated every generation, collapses the number of ancestors.

* See the popular idea called “Miller’s Law”, which is that in various psychological tasks including accurate immediate recall of an arbitrary list, the length limit is around seven items, plus or minus two; e.g. on Wikipedia

94 thoughts on “The Theory of Eight Surnames

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