Pedigree Collapse

[webwiz]

We all have two parents and 4 grandparents. We will have 8 great-grandparents unless our parents are first cousins. so the maximum number of direct ancestors doubles with each generation, but this maximum cannot be maintained for many generations because the number soon becomes greater than the population. So we know that most of our ancestors were reasonably closely related to their spouses. I have seen one estimate that, on average, any two randomly selected people will be 6th cousins.

Knowing this, I am slightly surprised that in my own tree of over 4000 people I have not found a single confirmed case of a marriage between related people. Has anyone else?

 

[Britjan]

I only have about 1750 people on my tree but down my paternal direct line I have two instances of cousins marrying. The first occurred around 1800 so is harder to prove , Joseph and Elizabeth the offspring of two brothers married. One of their sons another Joseph married Emily and her sister Elizabeth married Charles. Around 1870 Joseph and Emily's daughter another Elizabeth married her cousin James Charles son of Elizabeth and Charles. There is a lot more support in the way of records about this couple who are my great grandparents.

 

[AdrienneQ]

I have a great Aunt and Uncle who were cousins and married in 1932 they shared common Grandparents Thomas Smith Hesketh /Elizabeth Biddulph Johnson

 

[Bryman]

So we know that most of our ancestors were reasonably closely related to their spouses. I have seen one estimate that, on average, any two randomly selected people will be 6th cousins.

Knowing this, I am slightly surprised that in my own tree of over 4000 people I have not found a single confirmed case of a marriage between related people. Has anyone else?

Can you remember where you saw the 6th cousins estimate and perhaps how they arrived at that conclusion? That suggests much closer relationships than I would have expected. My most distant cousin identified so far is only at the 5th level but I have often wondered if more distant cousins are really meaningfully related at all.

Having said that, I have a smaller recorded tree than Britjan and have still found two separate instances of 1st cousins that married in the 19th century (two Kelsalls in 1852 and two Kembles in 1871). Perhaps my family did not get out and about as much as others.

 

[webwiz]

Can you remember where you saw the 6th cousins estimate and perhaps how they arrived at that conclusion? That suggests much closer relationships than I would have expected. My most distant cousin identified so far is only at the 5th level but I have often wondered if more distant cousins are really meaningfully related at all.

Having said that, I have a smaller recorded tree than Britjan and have still found two separate instances of 1st cousins that married in the 19th century (two Kelsalls in 1852 and two Kembles in 1871). Perhaps my family did not get out and about as much as others.

It was professor Steve Jones, I think he has the chair of biology at London University. 6th cousin is not really that close, they share one or two of 128 5g-grandparents who were probably living in the 1700's when people did not move around much and the majority lived in quite small rural communities. I would expect that the average relationship will be getting much more distant in modern times after the industrial revolution with the consequent growth of towns and cities and the railways which facilitated movement of people. In 200 years time our descendants will, on average, be hardly related at all.

 

[AdrienneQ]

In the case I mentioned earlier the surnames were Hesketh and Dew - remember when looking for family marriages the cousins don't necessarily have the same surname.
Another family link may be where a man marries two sisters therefor the children are siblings and some are cousins. I have had this happen a couple of times. I suspect 1st Wife dies, younger sister comes in to help look after the children and nature takes it cause.

In more modern times I know of a couple who remarried when they both had older children who later married.
This mean that after the wedding when the Father of the bride escorts the Mother of the groom out of the church, my friend and her husband where together- if you see what I mean.

 

[Britjan]

OK this took some doing but here is the original article and in it Prof Jones says " There were, for example, around 30,000 predicted fourth-cousin pairs (a shared great-great-great-grandparent). As a result, taking all family ties into account, the person you sat next to on the bus this morning is, on average, likely to be something like your sixth cousin, which means that the two of you probably share at least one ancestor from the time of the Paris Commune " Personally I think that's a bit of an exaggeration because even in relatively closed communities where cousins more traditionally married (for example Ashkenazim Jews) you often have to go back to the 4th or 5th remove to discover the common ancestor.

However this doesn't make your query any the less interesting if you look at the numbers of possible known ancestors you need to identify and the challenges of finding them. Part of that challenge is that if we don't recognise a name that comes across our radar we miss the possibility of being related to what appears to be a random stranger. Ancestry lets me know when one of my lovely "cousins" updates her tree of about 3800 which she maintains on behalf of very extended family. Since a recent name was unfamiliar I looked at the handy relationship guide. This new addition a Mr Steel is the father-in-law of a 2nd cousin 2 x removed of a wife of 2nd cousin 1 x removed (!) You would have to go back to the wife of the 2nd cousin who I have identified on my tree to find a "connecting" name but I did look to see if the other names along the way meant anything to me, and they didn't. They were mainly West country folks as well so no geographical nudge to make me sit up and take notice. So the dilemma I think is do I add all of them to my tree in the hope of a future connection? I am not a fan of huge trees because my own branch will be so puny but it is food for thought.

 

[Liberty]

One set of My GG Gparents were first cousins. One of my GGF's married his sister in law (2 brothers marrying 2 sisters).
Apart from the direct line, there are innumerable other sets of pairs of siblings marrying, marriage of cousins (first and more distant), men marrying the deceased wife's sister (which I think was VERY common - someone had to look after the children and it wouldn't be proper to share a house with your unmarried sister-in -aw). The most unusual one in my tree, I think, is brothers marrying a mother and daughter.

 

[Britjan]

Finding cousins that married might be thought to depend on a complete family tree going back four generations and Webwiz said in another part of the forum..."If someone has failed to find their 1st cousins (3 generations) or 2nd cousins (4 generations) then they either have been very unlucky or they have not been looking very hard, as the mother's maiden name is shown on births from Q3 1911."
My intent in joining the thread was to encourage those who have most of their family outside the UK to join in and I disagree with any implied emphasis being put on a mainly British (and then mainly English and Welsh) connection and the remarks about diligence and luck. I estimate that my tree by Webwiz's definition is only about 50% complete.
In my case with all the diligence in the world even if some branches of a family show up on the 1881 British census it is hard for example to overcome variations in spelling that come and go, emigrating to the dominions and back, leaving Ireland and likely dropping "o" from a name, moving to London, and the fact that by 1830-40 a large number of cousins had likely left East Anglia pausing only briefly in Canada en route to the U.S. Many forum members likely have the same hurdles to overcome so although my tree is far from complete I feel very lucky to have found the two sets of cousins I proudly displayed here. All I started with was a photo of James Charles inscribed with his birth and death date (1850-1911) and profession, found his marriage certificate and then the census showing that Elizabeth his wife had a father born in Canada. Joseph junior (1821-1893) returned to show up in the 1841 census and I was home and away from then on. The ancestors of James Charles are proving much more tricky because he seems to have changed a vital consonant in his name by the time he married and various hand written documents are subject to interpretation.
If only I could sort out the Irish question, a major move to London and the move from East Anglia to foreign parts along with name changes I might make more progress but then I expect to continue to be lucky as well. I am happy to share that luck with all on this thread on their cousins marrying search because you'll likely find something much more interesting than the fact that they married.

 

[webwiz]

OK this took some doing but here is the original article and in it Prof Jones says " There were, for example, around 30,000 predicted fourth-cousin pairs (a shared great-great-great-grandparent). As a result, taking all family ties into account, the person you sat next to on the bus this morning is, on average, likely to be something like your sixth cousin, which means that the two of you probably share at least one ancestor from the time of the Paris Commune "

That's good googling!

"Ancestry lets me know when one of my lovely "cousins" updates her tree of about 3800 which she maintains on behalf of very extended family. Since a recent name was unfamiliar I looked at the handy relationship guide. This new addition a Mr Steel is the father-in-law of a 2nd cousin 2 x removed of a wife of 2nd cousin 1 x removed (!) You would have to go back to the wife of the 2nd cousin who I have identified on my tree to find a "connecting" name but I did look to see if the other names along the way meant anything to me, and they didn't. "

I was only talking about blood relationships. If you add in relationships by marriage the effect is even more pronounced.

 

[webwiz]

Well it seems that most people have little trouble finding marriages between related couples, which accords with theory. Maybe my tree is unusual or maybe I have not looked hard enough.

Britjan is right in pointing out the problems if ancestors come from abroad. I have a few lines which look as if they originate in Ireland and I have made no progress at all on those, but they are all further back and the closest relative I could have would be a 3rd cousin.

 

[Bee]

I too have several first cousins who married, at least two or more generations ago. I also have a connection between my mother's line and my father's line three generations before they connected. So I suppose that shows something towards the 6th cousin theory.

 

[peter]

Well it seems that most people have little trouble finding marriages between related couples, which accords with theory. Maybe my tree is unusual or maybe I have not looked hard enough.

I suspect that the marriages between cousins that I've succeeded in identifying in my tree are just the tip of the iceberg - the chance of two 3rd cousins having the same surname is so low (probably about 1 in 300) that most cousin marriages simply aren't going to be noticed.

 

[Alexander Bisset]

Well it seems that most people have little trouble finding marriages between related couples, which accords with theory. Maybe my tree is unusual or maybe I have not looked hard enough.

It is more likely that you have done what almost everyone does, when you get a marriage into your line you don't follow the family of that related by marriage person as after all its only a relation by marriage. What Peter is alluding to is that if you were to trace all the people who marry into your family back 3 or 4 generations and also trace all the brothers and sisters of all your family members and all their marriages and children then you would find links within 3 or 4 generations.

Most people don't trace "side" lines that deeply as they lose interest as the surname changes. However it's those side lines traced forward and back that would give you the 3rd/4th etc cousins marriages.

 

[Liberty]

It is more likely that you have done what almost everyone does, when you get a marriage into your line you don't follow the family of that related by marriage person as after all its only a relation by marriage. What Peter is alluding to is that if you were to trace all the people who marry into your family back 3 or 4 generations and also trace all the brothers and sisters of all your family members and all their marriages and children then you would find links within 3 or 4 generations.

Most people don't trace "side" lines that deeply as they lose interest as the surname changes. However it's those side lines traced forward and back that would give you the 3rd/4th etc cousins marriages.

I may be a bit pathetic but I do trace people at quite remove from my line.
As I have posted elsewhere in this forum, the people of Sheringham in Norfolk were a pretty closed community. By tagging up marriages and baptisms as I find them I create quite a convoluted tree BUT I do often find it doubling it back on itself. If you are including 3rd or 4th cousin as 'marrying your cousin' I would say there was pretty high incidence of it in Sheringham.

 

[emjay]

Most people don't trace "side" lines that deeply as they lose interest as the surname changes. However it's those side lines traced forward and back that would give you the 3rd/4th etc cousins marriages.

I like to trace 'side lines' but not always with the depth I would apply to 'direct' or 'blood'. This is fine for indication of background, but it sure sets off 'alarm bells' when
the tree reaches FTA ! I suspect some members have 'dropped' some 'side lines' because of this, and the research and data entry involved. With some tree software a tree
can be split/separated. In Roots Magic 6 for example, there is a drag and drop facility, and Peter has mentioned being able to prune selective branches off his tree.

It seems a shame to permanently delete branches of research from a tree; who knows what it may turn up ?

 

[SuzanneD]

I suspect that the marriages between cousins that I've succeeded in identifying in my tree are just the tip of the iceberg - the chance of two 3rd cousins having the same surname is so low (probably about 1 in 300) that most cousin marriages simply aren't going to be noticed.

And I think we'd probably find more of them going on still than we think, for that reason. I can think of at least one marriage between third cousins in one branch my family taking place within the last 20 years - although in that case they knew they were distantly related.

I also have one line of ancestors from a village where everyone of my family surname is descended from one couple in the early 1700s, so I have done a mini one-name study for the village. Over the years I've also traced the surnames that crop up frequently among spouses from the same village (even if not directly related to me), and as a result of doing so, I can see that distant cousin marriages were extremely common. Having said that, they might just be a family that preferred to stick close to home: my 3-g-grandparents (who emigrated to New Zealand) were first cousins *and* second cousins (as one of them was also the child of cousins from the same family). It may not surprise you to know that this branch of my family suffers from more little genetic annoyances than the rest put together.

These next examples aren't quite the same, but anyway... Two of my first cousins on my mother's side are also third cousins on my father's side. My father also has two or three sets of 'double cousins', as we call them. And I'll never forget the look on some other cousins' face (brother and sister) when we went to visit them and two school friends (also brother and sister) were round visiting: you guessed it, also my second cousins on the other side of the family and well known to me already!

 

[Katie Bee]

One set of my great grandparents are first cousins.

 

[Alexander Bisset]

I like to trace 'side lines' but not always with the depth I would apply to 'direct' or 'blood'. This is fine for indication of background, but it sure sets off 'alarm bells' when the tree reaches FTA !

I'm curious what "Alarm Bells" does it set off. I wasn't aware I'd programmed any audible alerts Seriously though there should be nothing unusual about having non direct lines in your tree nothing that FTAnalyzer would get upset about. If it is then it could be a bug that needs fixed?

 

[Liberty]

The main 'problem' with having very distant connections on my tree (as it appears on Genes Reunited) is people contacting me, hoping that we are closer cousins than is the case. This isn't really a problem, of course, and sometimes I am able to provide information that they didn't have, in which case it is all to the good.