Color Clustering: Working with "4th Cousins"

Please see an updated version of this post and more on the Leeds Method of DNA Color Clustering on my new website, www.danaleeds.com

If you haven't read my first two posts about the Color Clustering (aka Leeds) Method, read the original posts:

• Color Clustering: Creating Color Clusters
• Color Clustering: Identifying "In Common" Surnames

An example of Color Clustering using Excel

I thought this method would be too messy to work with 4th cousins. But, I figured out yesterday how to make it work: I built my clusters based on the shared matches of 2nd and 3rd cousins and then I just sorted the "4th cousins" into these clusters!  

Here are the steps I used:

STEP 1: Create a Color Cluster chart (see first post)

Using all of AncestryDNA's predicted 2nd & 3rd cousins (who share less than 400 cM with the test taker), create a color cluster chart. (Note: If you are not comfortable with spreadsheets, you can use colored pencils and paper or whatever you have on hand!)

Example of test taker whose DNA sorted

into 4 Color Clusters plus one 

Unclustered (purple) match, Drew

Depending on which relatives have tested, Color Clustering often results in 4 columns which are related to the four sets of great grandparents. See the original post for examples and possible explanations of cases where there are not 4 columns created. 

Note: One match, Mona (red print), sorted into TWO columns. She most likely is related to the test taker through BOTH the yellow and orange families.

STEP 2: Identify these columns if possible.

In this case, we were able to determine the relationship of the test taker to the 4 clusters (C1 through C4). If you cannot identify some (or any) of these groups, you can skip this step.

STEP 3: Compare 4th Cousins Shared Matches to your Color Cluster Chart

Color Clustering using 4th Cousin Matches
(last 10 in grey).

Below the original Color Clustering, I wrote the names of the test taker's first ten "4th cousin" matches (in grey boxes). For each person, I opened the Shared Matches and looked to see which 2nd and 3rd cousin names they matched with and assigned them that color. Note: This is not proof that they are related to that branch of your family, but it is a strong clue! (I do not continue to add more columns; I am only determining which color cluster these matches match!)

STEP 4: Sort 4th cousins who do not have 2nd or 3rd cousin matches by looking at their shared matches.  

Showing 4th cousin, Teresa, had a shared
match that matched Mona so she was
assigned to both the orange & yellow clusters.
.

One 4th cousin match, Teresa (in red print), did not have a cousin within the 2nd and 3rd cousin matches. But, when I opened the shared matches of her closest match, she matched Mona. Since Mona is in the Orange & Yellow clusters, Teresa was assigned to both clusters.

Note: As with most techniques, this method works best when the branches of your family - especially your 4 sets of great grandparents - are completely unrelated. But, one of the neatest thing about this method is that your matches do NOT have to have FAMILY TREES and this will STILL WORK!!

Note: While the above example uses real data, the names have been changed for privacy. Also, this test taker had a single random person in a 5th column without a tree or any 2nd/3rd cousin matches. We have not identified this "unclustered" Purple match.

Happy Sorting!