I talked to a Pakistani friend of mine today. We, civilized people, do NOT understand the Arab, Mid eastern mind. They do not grasp capitalism, democracy, free will. Sharia lays out , (for instance 1..2..3..) and nobody can argue with it. We, on the other hand, have laws against murder, for instance, but in degrees (for instance 1st, 2nd, 3rd, manslaughter, accidental etc.) and these people just CAN NOT absorb this.
In Pakistan, about half of all registered marriages are between first cousins.
This is widespread in Islam, and has been going on for centuries.
This madness could well be driven, in part, by inbreeding.
Amazing that this is not very well know, the custom of marrying close relatives in Islam.