FREE June 8th NYG&B Webinar Focuses on Endogamous DNA Matches

DNA expert Paul Woodbury presenters "Strategies for Dealing with Endogamy" on June 8, 2022 for the New York Genealogical and Biographical Society.

Do you have endogamy in your family history? Do you have a DNA test with one of the major autosomal DNA testing companies? Or, if you’re like me, you might manage many DNA tests for family members across a number of the testing companies.

If you answered yes to both questions, you need to be aware of how endogamy in your family history can impact your DNA match lists.

What is Endogamy?

Not familiar with the term endogamy? ISOGG (the International Society of Genetic Genealogy) defines endogamy as:

…the practice of marrying within the same ethnic, cultural, social, religious or tribal group. In endogamous populations everyone will descend from the same small gene pool.1

What this boils down to is that some populations groups have a history of traditionally intermarrying among a collection of family groups. No, this does not mean necessarily siblings marrying siblings. But this might very well pertain to 3rd cousins, or 2nd cousins 3 times removed. Way back in time, all population groups intermarried, but then human migration started scattering people across the globe. However, even after that, some population groups continued to marry within their own community, whether that be due to geographic remoteness or more deliberate reasons.

From my personal family history perspective, Mexicans have traditionally been endogamous. So those of us of Mexican descent frequently come across this situation when researching our family history, whether through paper trail records or DNA. Mexicans are not the only ones though. Examples of other endogamous communities include: French Canadians, Cajuns, Jews, Mennonites, Amish, and some other Latin American population groups. This list is not exhaustive.

The family line of my own that I most heavily research is my dad’s line from the state of San Luis Potosí in Mexico. Our families have lived for centuries in a small beautiful rural rancho called Temaxcal. Historical records as well as family knowledge tells us that our rancho community is heavily endogamous. Those who still live in Temaxcal or have family that live there, as well as those of us who have studied the rancho and regional history are aware that most of us Temaxcal descendants are related in multiple ways. 

The Problem of Endogamy and DNA Matches

 Aside from endogamy being an interesting cultural situation to study, and one that helps you perhaps understand the relationship pathways you might discover in historical records, genealogists who research endogamous populations encounter a challenge when it comes to our DNA matches. 

Endogamy can inflate the estimated relationship ranges that the genealogical DNA testing companies calculate for autosomal DNA matches. For example, a match list might tell you that a match is an estimated 3rd cousin, when that match in fact shares a closest relationship pathway with you much further back than that 3rd cousin range. 

If you are not aware of this situation, you will not be able to successfully work your match list.

Dealing with endogamy among your DNA matches requires an awareness of its impact on your match list, and familiarity with strategies to deal with that impact.

About the Webinar

This June 8th webinar should provide you with a good free introduction to dealing with endogamy in your DNA matches. I have attended presentations by Paul Woodbury on this topic before. Reserve your free spot by registering today.

Are you looking for a deeper dive into learning how to work with endogamy among your DNA matches. Stay tuned for my next recommendation on this topic!


  1. International Society of Genetic Genealogy Wiki, (, “Endogamy,” rev. 20:45, 10 July 2021.

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