In 2018, we updated the Ancestry Composition Report to include new regions — your country matches — around the world. Country Matches will provide you with information about your more recent ancestry, giving you insight into countries and administrative regions within those countries where your ancestors likely lived.
In 2020, we introduced Genetic Groups — which provide more information about where your ancestors may have lived, what ethnic groups they may have identified with, or what languages they may have spoken.
Assigning Your Country Matches and Genetic Groups
Country Matches
To determine your Country Matches, we first define the reference populations for those countries using self-reported countries of ancestry of 23andMe customers as well as the self-reported countries of ancestry of individuals in publicly available reference datasets. For example: people whose four grandparents were born in the same country may be selected as a reference individual for that country. To determine if you may also have recent ancestry from a country or territory, we look for identical pieces of DNA that you have in common with those reference individuals.
Genetic Groups
To determine your Genetic Groups, we first identify groups of people with significant genetic similarity to each other. Then we define or label these Genetic Groups based on the self-reported information about individuals in those groups, such as their or their ancestors’ birth locations, languages, or cultural affiliations. These Genetic Groups then serve as a reference, representing groups of people whose ancestry is associated with shared ethnic identities, shared languages, or other self-reported characteristics. To determine if you share significant genetic similarity with any of these Genetic Groups, we look for identical pieces of DNA that you have in common with the reference individuals.
For both Genetic Groups and Country Matches, reference individuals are anonymized for their privacy and data security.
Your Country Matches and Genetic Groups (found within your Ancestry Composition results) are intended to complement your ancestral breakdown and provide a more recent and granular view of your ancestry. Results could reflect your connection to a recent ancestor or ancestors from a particular location, or it could provide insights about connections to people who identify as belonging to a particular ethnolinguistic group or speak a certain language (some genetic groups are based on a shared language or culture).
In order to be assigned a Country Match or Genetic Group, you must share identical DNA segments with reference individuals of known ancestry from that group or location. These initial steps determine the percent genome shared between you and the reference individuals for each Genetic Group or Country Match.
Match Strength
Your Country Matches and Genetic Groups are not assigned to you as percentages. Instead, they are assigned at different confidence levels based on the number of individuals from that group with whom you share DNA and the total amount of DNA you share. You can have a possible match, a likely match, or a highly likely match.
The strength of the match is determined by how much of your DNA you share with people from that group, calibrated by how many reference individuals there are. For a given Genetic Group or Country Match, we indicate our confidence in the result. "Possible" means we are between 30% - 50% confident in the assignment, "likely" means we are between 50% – 80% confident, while "highly likely" means we are at least 80% confident in the assignment. "Not detected" means we are less than 30% confident in assigning that match to you.
Ancestry Map
The map in your Ancestry Composition report is there to help you understand your ancestry percentages, Country Matches, and Genetic Groups, and to see where those reference populations are located around the world.
In some cases, you may also see evidence of ancestry from more specific subregions within a Country Match, down to the state or even county level. The shaded subregions within each country or territory are where we have found evidence of your family’s recent ancestry. The stronger the evidence of ancestry, the darker the shading is for that region.
If you have a match to a Genetic Group, you will see a regional outline on your map that represents where their recent ancestors were born. Unlike your Country Matches, these outlines typically do not exactly match geopolitical borders.
Keep in mind these outlines cannot show you where your ancestors lived with certainty. They can only reveal where your ancestors may have lived, because we use the ancestor birth locations reported by reference individuals as a proxy. This means that it is possible that the geographic locations of your shared ancestors may differ from the regions shown on the map. This may be due to major historical migrations and other events, which can result in initially surprising or unexpected results.
Common Questions
Why don’t I have any Country Matches or Genetic Groups?
If you don’t share the minimum number of identical DNA segments with our reference individuals and/or the percent of your genome shared with our reference individuals does not pass our confidence thresholds, then you will not see any additional Country Matches or Genetic Groups within your Ancestry Composition Report. Keep in mind that Ancestry Composition can be considered a living analysis, so you may see more detail added in the future as new matches are detected or as new Genetic Groups are added.
A high percentage of my DNA is assigned to a particular ancestral population. Why don't I have high match strength with any of the associated Countries or Genetic Groups listed in my results?
To assign your Country Matches and Genetic Groups, we look for identical pieces of DNA that you have in common with a large group of individuals with known ancestry from many regions worldwide.
The more DNA you share with reference individuals from specific countries or genetic groups, the higher the likelihood is that we can assign those countries of ancestry and genetic groups to you. However, you may not have enough DNA shared with reference individuals for us to make an assignment with confidence.
The likelihood that a Country Match or Genetic Group will be assigned to you depends on other factors as well, including the region’s genetic history. For example:
- On average, people from a smaller, more homogenous country like Iceland will share more DNA with each other than people who come from a larger, more diverse country like China. As a result, it may be more difficult for us to identify ancestry from certain countries than from others, depending on their population history.
- Additionally, if you are from a group within a country that is not common in our reference dataset or is very genetically similar to other countries for which we have larger sample sizes, it is less likely that you will get a match you expect.
- Country borders have changed a lot even within the past 100 years, which can sometimes produce confusing results. For example, country borders in Eastern Europe and the Balkans changed dramatically with the dissolution of the Soviet Union in the last decade of the 20th century.
I have a parent genotyped. Do you know which side of my family a match to a country or genetic group came from?
No, while we can determine that a match exists to a country or genetic group, we don't know which copy of a chromosome (or, which side of your family) that match occurs on. This is because your phased chromosomes are not used to find matches.
Will you add more Country Matches and Genetic Groups over time?
Yes, we hope to add additional Country Matches and Genetic Groups. You can consider your Ancestry Composition a living analysis, so your report may change over time. If new matches are detected or new locations are added, these will be added to your report.
Why did my Country Matches or Genetic Groups change?
The set of reference individuals we use to calculate your matches to countries of ancestry and genetic groups are updated occasionally to include new reference individuals, so you may see your matches change as the size of our database grows. We are constantly working to improve this calculation in a way that is more precisely calibrated to each reference group.