I've come from a country were cousin marriage and indeed marriage to any close relative if illegal.
I've recently started working in a dialysis unit and I'm so disturbed by how many parents are young children born of first cousin marriage. Usually from South Asian backgrounds.
Today I was speaking to one parents who has 9 children, all in need of kidney transplants. The eldest 2 have already had theirs. Parents are first degree cousins and each have various medical problems of their own.
Why, as a society, do we allow these marriages? It seems so cruel to the children who are born with medical and genetic problems.
Maybe I'm easily shocked, I don't know.