Inbreeding... and a little incest

[Formendacil]

Originally Posted by Lindale

So why don't the Elves get a little wacko with all their inbreeding? And Eldarion too?

To focus merely upon Eldarion for the moment... I wouldn't worry about him. Aragorn was so many generations (around 60) removed from Elros that his percentage of shared ancestry with Arwen, taken as a percentage of his overall ancestry, can't have been at all worrisome...

And, while a certain amount of inbreeding certainly exists (especially among the descendents of Elwë, Olwë, and Elmo, who were brethren), I don't think there's any examples of marriages between first cousins or of those of equal or closer degree... which is the human norm for acceptable.