Sort of fits in with the perception that while most Muslims are bat$h*+ crazy, the Pakistanis are crazier than the Arabs and the Arabs are crazier than the Turks.
First cousin marriages are not unknown in America. In fact, they were fairly common not much more than 150 years ago due to isolation of many communities. I have one such marriage in my family tree within fairly recent times, a great grandmother.
She was a brilliant lady and many of her progeny became educators (my grandfather was a university science professor), military officers, inventors and the like.
The problem is not a first cousin marriage here and there, but a generation after generation thing where all the crazy genes become dominant. That's what we are seeing in the Islamic world, adding the handicap that they begin life subscribed to a crazy totalitarian set of values which can be modified only at great risk to their lives.
I still don't like any first cousin marriage. Did you read in my post were some Muslims like to go even further where a man marries the daughter of his brother? Holly cow!!! I am guessing this marriage is done for his second or third wife.