What's a Half Second Cousin?

A half-second cousin is a person with whom we share only one great-grandparent.

Are half cousins blood related?

It turns out they are cousins, because cousins share a common set of grandparents, the relationships between half-siblings parents don't affect their cousin relationships. This extends through all generations. ... Half 1st cousins share 6.25% of DNA, while full 1st cousins share 12.5% of DNA.

How much DNA do half cousins share?

The short answer is that your son and his half cousin are going to share about 6.25% of their DNA. Notice the about here… Every kid gets half of their DNA from their mom and half from their dad.