This article explains why you may have noticed changes in your predicted relationships.
How does 23andMe predict relationships?
The DNA Relatives feature is one of the most interactive features of 23andMe, allowing you to find and connect with genetic relatives and learn more about your family.
Relatives are identified by comparing your DNA with the DNA of other 23andMe customers who are participating in the DNA Relatives feature. When two people are found to have an identical DNA segment above a certain length, they very likely share a recent common ancestor. The DNA Relatives feature uses the length and number of these identical segments to predict the relationship between genetic relatives. Learn more about DNA Relatives.
As part of our ongoing efforts to improve customers’ predictions, we’ve pioneered a new relationship prediction algorithm that is able to more precisely estimate your genetic relationship with some of your closest relatives. This new algorithm allows us to look at multiple relationships within your family tree all at once, calculate the many different ways you could all be related to each other, and then estimate the most likely relationships out of all the possibilities we calculated.
As a result of these improvements, some of your relationship predictions may have changed.
We recalculated some of your relationship predictions to build your Family Tree, so you may have noticed a change recently. Predictions for relationships with similar amounts of shared DNA may have changed, because the new algorithm uses evidence from many relationships all at once to select the most likely option. Furthermore, predicted relationships may now include half-cousin relationships as well as “removed” relationships. (Example relationship: first cousin once-removed. Read more above.)
|Example updates to relationship predictions|
|Before Update||After Update||What's New?|
|“2nd-4th cousin”||“2nd cousin once-removed”||Considers “removed” relationships|
|“3rd-to-6th cousin”||“3rd cousin”||Single prediction instead of a range|
|“2nd cousin”||“Half first cousin”||Considers half-cousin relationships|
Why did I lose some of my relationship edits?
You may also see changes to close relationships that you previously edited. In predicting your new family tree relationships, we recalculated the relationship for each person from scratch, because we know that the relationship labels we provided for our users in the past didn't cover all the true relationships they needed. For instance, participants with a half-uncle (about 12.5% shared DNA) only had the options to leave the "first cousin" (about 12.5% shared DNA) prediction or select "uncle," (about 25% DNA shared). Many users chose "uncle," but if we used that relationship to build the new trees, that inaccuracy could cause additional inaccurate predictions throughout the tree.
The tree now provides you with the ability to create a more diverse set of relationships, including "half" and "removed" versions of any relationship (like a half-uncle). For tips on how to edit relationships in your Family Tree, visit our guide: How to build and edit your Family Tree.
Commonly asked questions
Can I revert to my old edited relationships?
Yes. You can re-edit relationships by moving the relative to the proper position in your Family Tree. Or, you can use the relationship editing drop-down menu on the relative's profile page to change your relationship label. When you change the relationship label using the drop-down menu, you will then need to add them back to your tree in the correct position. Learn how to make edits in your Family Tree.
If I opt out of DNA Relatives, what happens to the data in my Family Tree?
When you opt out of DNA Relatives, your Family Tree will still be available, but only with relatives whom you have directly connected with, or relatives whom you have manually entered into your Family Tree.
Any information you have manually added about your ancestors and other relatives will not disappear. In addition, DNA relatives will no longer have permission to view you. As a result, they will no longer see you or your tree, unless you have directly connected.
If I edit a relationship in my Family Tree, will that edit be reflected in my list of DNA relatives?
Yes. If you edit a predicted relationship through the editing tools available in your Family Tree, then the corrected relationship will be shown on both your Family Tree and your DNA Relatives list.
If I edit a relationship on my relative’s profile page, will that change be reflected in my Family Tree?
No. If a genotyped relative is already on your Family Tree, editing the label of your relationship via the profile page will remove them from your Family Tree. You will then be prompted to manually add them back to your tree by selecting a new position for them.
You can add any DNA relative to your family tree at any time using the prompt to "Manually add to tree" below your relationship information.