“Parallel-Cousin (FBD) Marriage, Islamization, and Arabization”, 2000-09-01 (; similar):
Islamization, along with an area’s inclusion in the 8th-century Arab-Islamic Khalifate (and its persistence within the Islamic world) is a strong and statistically-significant predictor of parallel-cousin (FBD) marriage. While there is a clear functional connection between Islam and FBD marriage, the prescription to marry a FBD does not appear to be sufficient to persuade people to actually marry thus, even if the marriage brings with it economic advantages. A systematic acceptance of parallel-cousin marriage took place when Islamization occurred together with Arabization.
[Keywords: cross-cultural research, Middle East, marriage, Galton’s problem]