Am I inbred if my grandparents are second cousins?

Is It Common for Grandparents to Be Second Cousins?

Yes — and you’re likely just fine. The idea that second cousins marrying leads to serious genetic risks is often overstated, especially when it’s just a single occurrence in a family tree. In fact, throughout much of human history, people married within their communities, which often meant some degree of distant kinship. Second cousin marriages were not only common but sometimes even encouraged to keep families connected or preserve inheritance lines.

Genetic diversity matters more than a single instance of distant relation. The real concern arises when families have intermarried over generations — think multiple close relatives marrying over centuries — which can limit the gene pool and increase the chance of inherited conditions. But if your grandparents are simply second cousins, that’s a pretty minimal connection. Genetically speaking, you’re likely no more at risk than anyone else.

Second cousins share about 3.125% of their DNA, on average. That’s a small fraction compared to first cousins, who share around 12.5%. With modern genetic understanding, we know that the risk of birth defects or health issues from second cousin unions is only slightly higher than in completely unrelated couples — and often not significant enough to cause concern.

So, if your grandparents are second cousins, you’re far from alone in that situation — and there’s no reason to worry. Millions of people around the world come from similar family backgrounds. What matters most is the overall health and diversity of the lineage, not a single distant link. In the grand story of your family tree, this detail is more a footnote than a red flag.