You're right Neil. Ignorance is probably the biggest world-wide phenomenon. Except I guess in Saudi Arabia, they would be called dark necks rather than red necks (color complexions).
Although to play the devil's advocate, I'd have to say that I'm sure that the vast majority of Saudis don't PREFER to marry their cousins. There are Saudi students here and most of them are just as enlightened as any good ol' American boy that goes to University. Don't let propaganda fool you.