Leeds Method: Lack of 2nd Cousins Can Cause Lot of Clusters
I recently discussed how and why you might need to consolidate your clusters when doing the Leeds Method. I also shared an example and went through the process step by step.
But even after consolidating your clusters, some of you will still have more than 4 clusters. In fact, some of you will still have quite a few clusters. But, why? Well, for many of you it’s because you don’t have any—or don’t have enough—2nd cousins.
Why Second Cousins?
The Leeds Method attempts to use 2nd and 3rd cousins to sort your DNA matches into groups of people who are closely related to each other. In a best case scenario, your chart will have 4 clusters with each of your 4 clusters representing a grandparent line. But, most people need 2nd cousins to make this happen. Let’s discuss “why.”
We all have 4 grandparents and 8 great grandparents. Our (full) 1st cousins share a set of grandparents with us. They are either on our dad’s side or on our mom’s side.
If we sort our cousins based on 1st cousins, we would potentially get two groups. One group would represent our dad’s side of the family, and the other group would represent our mom’s side of the family.
Our (full) 2nd cousins share a set of great grandparents with us. They are either on our dad’s dad’s, dad’s mom’s, mom’s dad’s, or mom’s mom’s side.
If we sort our cousins based on 2nd cousins, we potentially get four groups. This is because our 2nd cousins are the descendants of our grandparents’ siblings. And that is why we use 2nd cousins in the Leeds Method.
Since our cousin lists are built on shared DNA, the Leeds Method uses 3rd cousins to fill in some of those DNA gaps.
NOTE: If you know who some of your matches are, you want to skip any who share more than one grandparent with you and use any who share only one grandparent with you! (I’ll be blogging about this next.)
Example
Here’s an example of a Leeds Method chart that has 19 people sharing between 90 and 400 cM. However, instead of the hoped for 4 clusters, this chart has 8 clusters. It also has no overlap. In other words, each person sorted into only one color cluster group.
If you look at the numbers on the left hand column, you’ll see that these numbers are on the low side of the recommended range of 400 to 90 cM. Many of these matches are likely 3rd cousins. If we don’t have 2nd cousins to “tie” our cousins together, we will get more clusters.
Next Step
No matter how many clusters you get, your next step is to figure out what each cluster means. If your biological parents and grandparents are known, you are trying to figure out which grandparent or great grandparent the group represents. If your biological parents or grandparents are unknown, you will want to work with the matches in the group and see how they connect to each other.
I hope this helps! And, as always, feel free to write and ask me your questions!
Thank you very much for this. I struggle with the fact that all lines, but my maternal grandmother’s family have a common ancestor.
There is so much overlap in my tree that it makes things difficult.
I found the Leeds method helped out, I have over 140 individuals that fit within the parameters of the Leeds method.
Now if I could just get through my eternal Irish brick wall!
Unfortunately, having common ancestors over multiple parts of your family tree makes working with DNA quite difficult! If you’ve not already watched it, I recommend Paul Woodbury’s “Dealing with Endogamy” video on Family Tree Webinars.
One key outcome of the Leeds Method, is that almost certainly each of the groups will represent a different Ancestor. As you figure out some of them, that reduces the possibilities for the others.
Great point, Jim! Thanks for pointing that out.
Dana, I have 12 matches at Ancestry they label as “2nd Cousins,” but that group actually contains people who are my 1C1R and 1C2R (most are my father’s siblings’ grandchildren and great-grandchildren). I have true 2C matches in the group Ancestry labels as “3rd Cousins.” I wonder if the issue for some is that they actually do have 2nd Cousins, but Ancestry’s sorting of the matches is not correct for some people?
Hi, Lisa. Ancestry can only guess at a relationship so, as you pointed out, sometimes our “once” and “twice removed” turn up in the wrong category. If you don’t know your family tree or matches, these categories are a great place to start. But, if you do know these matches, then you can determine their relationship and decide whether or not to use them.
Yep, us older people are pretty likely to have 1cxr tested where we are the closest to the common ancestor. Their shared matches list spans multiple groups. I have a 1c1r with whom I share 399cm so using his test combined many tests of my great grandparents on my dad’s side. Once I ignored his test things leveled out, still several low cm groups due to pedigree collapse and endogamy but much better. (I’m not sure endogamy is the right word where several descendants of one of one’s ancestors marry descendants of another of one’s ancestors making one related through multiple paths not resulting in pedigree collapse of one’s own ancestors. For instance a 4c on my dad’s side married a 3c on my mom’s side, consequentially I share more DNA with that person than either my mom or dad.)
Gary, Yes, age (or at least generational age) does affect where our 1CXR may fall and can affect our Leeds Method charts! That’s why it’s important to only use those matches who share one grandparent line with you IF you know your cousins. And, it’s important to do “check your work” which I need to write about more.
I must have read Gary’s comment differently from the way you did. It sounds like his tree has distinct ancestors and not have pedigree collapse, but that he has some double cousins, kids of a paternal 4C and maternal 3C.
Thanks for the additional blog post. It’s always good to have clear writing on such a powerful technique!
William, I went back and reread Gary’s comment. He did say the marriage did not result in pedigree collapse of his own ancestors. It does not sound like these are his direct ancestors, so I believe you’re right! I’ll correct my comment. Thanks for pointing that out!
I’m trying to find an unknown paternal grandfather (father’s father), most of the known matches are from the maternal side (mothers mother and father). Would you recommend leaving out all of the mothers family out?
Also trying to find anything on my father-in-laws fathers family on his father and mothers side. only thing that is known is their names, if that’s even correct. If i’ve done LEEDS correctly, i come up with only 3 groups, after consolidating. I wonder if a man was married twice, with children from both, so one group overlaps but would actually be 2 groups? is that possible?
Hi, Katherine. I usually recommend using all of your 2nd and 3rd cousins (or matches from 90 to 400 cM) to create your initial chart – even if you know some of them are on the wrong side. THEN you can concentrate on the “unknown” clusters. There might be some crossover that you might not notice otherwise!
And, yes, your theory is possible. Or it could be from just one marriage but the DNA just doesn’t overlap so you have 2 groups.
Now that you have your clusters, work with them to see who the members are and how they’re related to each other.
Best wishes!
Dana
Is there a service that will assist with preparing a Leeds chart?
Hi! You can email me at drleeds@sbcglobal.net.
Dana
Hi Dana,
I have been working with my husband’s DNA to identify his paternal grandparents, his father was a foundling and was given a made up name.
I’ve been trying to work out the leeds method but, his closest match is only 167cm , will this still work?
In the 3rd cousin range he only has six matches at Ancestry and one at My Heritage .
Thanks,
Hi, Dianne. That does make it tough! I would go ahead and do the Leeds Method with maybe those 6 Ancestry matches and extend it to maybe a dozen. Do you get any clusters? Can you figure out if these clusters are related to his 3 known grandparents? Or are they unknowns? Your hope will be to find some unknown clusters. Also, do you have any higher matches? Or are there are relatives on the 3 grandparent sides who can test? That would help you figure out which matches are NOT part of this mystery line. Best wishes!
I am totally new to all of this. I knew nothing about my paternal heritage. With 23andme I had one second cousin match (221 cm) and a third cousin match (100 cm). These two were matches for one another. For the former person I had information including birthplace for himself as well as maternal and paternal grandparents and 3 surnames associated with his kin. That was enough for me to create a family tree linking those two individuals and that has me well on my way to sorting out my paternal line…..
It did take a fair bit of work and I goofed on one of the grandparents and did a long tree for the wrong family….I learned that when I reached out to the second cousin and he set me straight!
That’s great, Ian! You might also consider testing at Ancestry. They have a much larger database – and more trees to work with! Also, you can transfer your results for free to FamilyTreeDNA and MyHeritage. You never know where your closest match might show up, so we recommend being in all 4 “big” databases!
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Hi Dana
I’m helping my husband search for his maternal grandfather. His mom was adopted out of The NY Foundling Hospital in 1925. He did AncestryDNA and we received matches that helped us locate her mother’s side of the family. So far we haven’t discovered any matches on her father’s side of the family. There was a father’s name listed on her birth certificate but we have no way of knowing if the name is real or not. The adoption was kept a secret.
I’ve created a family tree for him & uploaded the tree and DNA results to Gedmath and My Heritage. I’ve did the Leeds Method twice organizing his DNA matches. Since he only had 19 matches between 400 cm and 90 cm I decided to go further down his list in the hopes of adding more names would help. Unfortunately I still only come up with three colors linking them to 3 sets of great-grandparents instead of 4 sets of great-grandparents.
Is this unusual? Is there anything else I can do to help him find any DNA matches that would connect back to his grandfather?
Thanks for your help
Anne, I can think of a couple of things. First of all, you can upload your results – for free – to FTDNA. I’d also suggest he test at 23andMe. When you’re working with adoption cases, you never know where that closest match will be!
Since you have a birth father listed on the birth certificate, you might try searching your matches for that surname. (Unless it’s very common!) That might help you determine if it’s a real name or not.
Also, if you can find this man in any records, you can research and see if he had any “other” children – maybe one of them would test so you could prove/disprove that he was the father.
Hope these ideas help!
Dana
Hi, I’ve created an excel sheet to do the clusters, and there’s evidence of overlap. I have only 4 groups but 2 groups overlap. So if I consolidate these, how then can I sift through to find a way to separate them? We’re looking for great grandparents who changed their names.
Emma, Is the overlap heavy? In other words, do most of the people in one cluster also show up in the other? Or are there just a few people in common? Either way, you can work with them as either 2 or 4 clusters. You need to identify why the clusters formed. In other words, how do the people in that cluster relate to each other? It might be there are 4 different relationships for the 4 clusters. Or there might really only be 2 clusters.
Your next job would be to identify which cluster (or clusters) include people who might be descended from this part of the family. Then start adding in more distant cousins – those Shared Matches that match the people in that cluster.
Best wishes!
Dana
Good morning,
Trying to find an absent grandfather. Mother was adopted (b.1928), have pinned down her birth mother but her husband abandoned her 8 years prior to mother’s birth. I’m going to have a problem finding that grandfather, aren’t I !
Thanks
Hi, Ange. This is actually what those working with DNA to find bio parents do all the time! A bio grandparent is a bit harder but often still doable. Did she take a DNA test? If not, do you have siblings who could also test? And, have you tested at Ancestry and 23andMe and transferred your data for FREE to MyHeritage and FamilyTreeDNA? Then you need to look for matches that don’t appear to match her birth mom’s side. If you have siblings then their DNA can help since they inherited DNA that you didn’t.
Best wishes!
Dana
Good Morning – I’ve been reading all of your blogs, sorting through them, making sure I’m on the right track. Working with an adoptee unknown parentage, LOTS of 1st cousin matches, understanding I work from 2nd-3rd cluster them then I could theoretically add back the 1st cousins via the match groups to sort out the grandparent lines. When I’ve worked a few other clients I had “one” parent or easily located them, this one lots of cousins so need to sort …. am I on the right track here 2nd-3rds then sort in the 1sts with the colors they match? Thank you.
Hi, Linda. Having lots of 1st cousin matches can be a huge help in identifying unknown parents! Yes, you would still start with 2nd and 3rd cousins and then add the 1st cousins into whatever clusters they sort into.
If you have LOTS of 1st cousins, how many cousins are there in the 2nd to 3rd cousin range? My concern would be that you might be seeing endogamy and that these 1st cousins are actually more distant relatives that are related to the adoptee in multiple ways. If you aren’t finding quick connections between the first cousins, this might be the reason.
Dana
I’m having trouble. I made a column starting with the 1st person with less that 400 cMs. I have around 75 people that are between 400 and 90 cMs. I take the 1st person below the starting point and go to shared matches, the 1st person that comes up is the started person, it just keep jumping back an forth……how do I move this forward.
Thank you,
Merl
Hello Dana. I am searching for a biological father. I had two first cousin matches several years ago (brother and sister). They were contacted by ProGen at Ancestry, but declined any communication, then made their tree and DNA results private. I did copy their tree however, although I do not know which side I belong to. I do have the names of five men who are possibilities based on their ages and where they lived. I did my clusters today using your method. I did not have enough cousins in the cM range you suggested (only 5 …one also searching for bio. father, one adopted and not searching, one with no tree). So I added cousins but they are mostly fourths. I have 5 clusters at this time. The only surname match I have belongs to two of my matches, but they are in different clusters. I am wondering if I have done this correctly. Thank you. FYI I was given your name by a member of the Ancestry group on Facebook.
Hi, Lorraine. If you don’t have your DNA at all 4 of the big sites, that would be my #1 suggestion. You have to pay to test at Ancestry and 23andMe, but you can transfer your data – for free – to MyHeritage and FamilyTreeDNA. Hopefully you’ll get additional matches that might help! And, it might be possible to build out a tree for the match without a tree. You also can use smaller matches.
Hi Dana,
Will LEEDs enable me to find a great grandfather AND if the great grandmother was my grandfather’s mother or if he was born out of wedlock and given to my Smith great grandparents? I suppose there is an option that his mother was biological and she had conceived with the unknown great grandfather. My Y-DNA points to another line, not Smith.
Dave
Hi, David. The Leeds Method should help you with these questions. You want to create the clusters and figure out which cluster would be from that line. Then start “diagramming” (you can search my blog) the matches in that cluster and see how they’re related to each other. This should either lead back to the Smith family or to an unknown family.
Hope this helps!
Dana
Hi Dana
I am looking for my fathers dad, my mom and dad is first cousins. my dad have over 4000 relatives on his list and all of them is 3 to 4/5 cousin related.
highest 80 % cm and lowest 10%, he has about 36 1st cousin, of which 10 is over 100 to 360 cm, the rest is lower %. I have tested him and my mom on my heritage. could i also do the leeds method on the first cousins, but only those that would not include the persons that i know that is related to my mother? and up to which % can i go? i have selected 30% which gave me about 1000 people, my grandmothers were sisters, and their parents were cousins. thanks
I include both mom’s side and dad’s side even when I know some of the people. And, I wouldn’t do more than your best 50-100 matches. If you know a match shares more than one grandparent, though, then do not use them.
Dana
Hello Dana, I was adopted out at birth so I recently took DNA with Ancestry and 2 results came back as full sisters. CM for 1 was 2161 and the other CM was 2309 but both of them swear they are my half sister. I placed the chart together and have many overlaps was wondering if you could please help me. Thank you
(I reached out to Tami.)
what happens if there are no high matches…I am trying to find out who my paternal grandfathers parents were..its been my long time brick wall. the highest matches are only in the 60-70 cm range and a whole lot of lower matches below that range too. what can I do ?
Hi, Glenda. If possible, my top suggestion would be to get in the 4 major databases; you never know where your highest match will be! So, you have to pay to test at Ancestry and 23andMe, but you can transfer for free to MyHeritage and FamilyTreeDNA. Also, if you have any older relatives who are still alive – whether it is your father, aunts/uncles, or other descendants of this couple, then test them. I suggest Ancestry as my top testing recommendation. They have by far the largest database and the most number of trees.
Best wishes!
Dana
Would you be able to assist me with my maternal side? I am so dumbfounded as to which cousins just match on her dad’s side, vs which match both her mom and dad (I have double 1C1R, 1C2R, and 1CR from her dad’s youngest sister marrying my mother’s mother’s brother AND my mother’s mother’s sister married my mother’s father’s brother….) This is a nightmare!
I am working on my BFF’s Leeds method. She is adopted and doesn’t have any information regarding parents or family members. She has a 379 cm match and a 250 cm match. I’ve used the method with her 500 second cousins and there is so much overlap that I can’t see the forest for the trees. Her two highest matches are fairly distinct sides of the family, but even there, there is some overlap. I’ve used about 700 matches and I would say 90% are related to each other. Is this normal or do I need to go down to distant relatives to get four distinct clusters? Thank you! This method is wonderful and so clarifying in most instances. Do you do hourly consulting?
Hi, Cynthia. I usually use my dad’s DNA as an example as his results are somewhat “average” and each of his grandparents is a distinct lines. He only has 50 matches between 400 and 90 cM. So 500+ is a lot! That suggests that your friend likely has either endogamy, pedigree collapse, or possibly just large families. But, since you mention a lot of overlap, endogamy or pedigree collapse are likely.
I would suggest running a Collins’ Leeds Method report which can quickly handle all of those matches. And, yes, I do hourly consulting. So if you’d like help either running the report or interpreting it, feel free to email me at drleeds@sbcglobal.net
Dana
I am trying to find my great grandmothers family. She was taken in by a family and took on their last name but I’m pretty sure not an adoption. I do not know if she had siblings but not with this family. She was born in 1870. I find her on the 1880 census with this family, 1890 census lost, and by 1900 she was married to my great grandfather. She is from my mothers fathers side. What I have done so far is on ancestry.com. I found matches to my moms, moms side and marked them. Then I went to my mom’s matches that do not match on her mom’s side and assuming are from her fathers side. Are not very many but there is a 2nd – 3rd cousin. I’m thinking this would perhaps be a grandchild of a sibling of ggrandmother. I have tried contacting for about 9 months but don’t get a reply. The next matches are 4th – 6th cousins. Am I on the right track and how could I proceed with finding matches of a great grandparent?
Hi, Donna. It’s a good guess that those unknown matches are on her father’s side. I’m not sure if this is what you’re doing, but I would look at the Shared Matches of this 2nd-3rd cousin match that hasn’t been responding. Look at their trees and try to find a connection between them.
You also might want to transfer your results – for free – to MyHeritage and FamilyTreeDNA. You might have better matches at one of those sites! If you still aren’t finding what you need, you might consider testing at 23andMe as it is the 2nd largest site behind AncestryDNA.
Best wishes!
Dana
Hi Dana,
I am looking for a missing Great Grandfather. My grandfather has no father named on his birth certificate. Would I use the Leeds chart in the same way x would ‘half’ connections cause any problems with this?
Thank you
Louise
Hi, Louise. Yes, you would use the Leeds Method the same way when looking for a missing great grandfather. And half connections shouldn’t be a problem!
Hope it helps,
Dana
So, I have a question? If my grandmother had several husbands-and had children with each one-wouldn’t the grandchildren all be related by half to each husband? Or am I looking at that wrong. I understand they would all be connected through the grandmother-but what about each husband? If that makes sense?
Hi, Sandra. Let’s say grandma had 3 husband’s: A, B, & C. The children of A would be related through DNA to both grandma & A. The children of B would be related thorugh DNA to both grandma & B. But A & B are only related to each other through DNA they got from grandma (their mom). They don’t have any DNA in common with them based on their fathers.
Hope this makes sense!
Dana
Hi Dana
I am trying to find my birth father, but according to Ancestry matches, I have to go back to my 5th GGrandFather (on the paternal side) as a common ancestor, but the matches or between 6 – 8 cM is it possible to do the Leeds method, on this low DnA, or as it is looking my birth mother lied about who my birth father was on my adoption papers. My birth father maternal side is ok, plenty of matches.
Which makes me wonder what is going on, is there another method that I can use that uses lower DnA matches.
Thank you
Kind Regards
Gill
Hi, Gill. You shouldn’t have to work with those small matches to identify your birth father. How many cMs of DNA do your top 5 paternal matches share with you?
Dana
Dear Dana,
I would like your advice. During Covid I created a tree for my cousin Sue, our mothers were sisters. Her father, John Moore, was born in October 1916 to Laura Wells in Guysborough, NS. John’s father, Sydney Moore, (acc’d to the Canadian birth record,) had died in Cambridge. MA in January 1916 after the Grandma had moved back to Canada In 1920, grandma Laura died and John is sent back to MA, and with his older sister, was raised by foster parents.
The Moore family wanted to know about their grandfather, Sydney Burrill Moore. Finding the family in Cambridge, MA census, I created a line for Sydney (which was tricky due to a name change) and his family in Newburyport, MA, going way back to colonial times. Everyone was happy.
Last year however, Sue did her DNA which i managed and I found no DNA cousins connecting to Sydney’s MA ancestry, in spite of MA’s superior record keeping. It was too complicated to review this finding over the phone so I waited until we had a family meeting. First, I reviewed the documented lines, and then Sue’s DNA cousins and then “thru lines” via Ancestry, which showed no connections to Sydney Moore’s ancestors. I noted that it was abnormal that there were no DNA cousins related to Sydney, Sue’s grandfather, and we discussed that DNA results suggest “Sydney” isn’t John’s father.
So now I’ve used the Leeds method to come up with John’s Father’s (Sue grandfather’s) ancestry. The Leeds is all new to me. I read and watched videos, but I have no confidence in my work. After reviewing the sorted DNA cousins, I suspect the “bio” grandfather was from NS and there was a liaison with Grandma Laura, after she returned to NS. I recreated trees of the 10 closest DNA cousins and found all have someone from Gurborough, NS and have a hypothesis finding a guy who was alive, and living in Guysborough, in the proper time frame, but IDK.
Do you review this kind of thing or give direction? Where can I go for help of to have someone review my work? I’m not going to present any of this to my cousins as I have no clue if I have done this correctly. Any ideas for me? TMM
Hi, Teresa. I’ll email you.
Dana