Scandinavia and the World

Comments #9841461:

Old habits die hard 30 8, 4:07pm

@Cygnata Several years ago, I remember earing a biologist explaining that you need a liiiittle bit of incest in your genes, something like a grand-grand-grand parent in common. More (and less) incest makes a weaker child either by permitting diseases or weaknesses.

I've never been able to confirm that or no.