[ErnBatavia]

First cousins are borderline ok to marry. I'm not sure if all states ban them or not.

Yeah...this goofball said he checked out the legality of it all. He justified it by saying they'd never breed since "the factory is closed".

[SarahW]

You might be interested in this month's issue of Discovery maganzine...there's a big article on the subject.

Marrying first cousins can concentrate recessive traits, but it also has genetic benefits, like passing on adaptive traits, and concentrating desirable traits, and avoiding some of the risks of outbreeding.

It takes several generations of inbreeding for any substantial increase in the birth defect rate. The birth defect rate for first-cousin unions is not significantly different from an outbred union.

Essentially, human beings were designed to live in concentrated groups with some genetic linkage.