Re: marrying your cousin when your parents are first cousins..
It only raises the possibility of genetic abnormalities by 3% (out of 100%).
Personally, I think it's better to marry other people, because it brings in new blood, and new ties with other groups of people.
that 3% is it the first time a perosn marries their cousin, or is it after generation after generation of inter marriage?
someone gave an example of ashknazi jews and their medical problems as an example.