Trends in patrilineal parallel first cousin marriages among Israeli Arabs: 1949-1995

Consanguineous marriages are one of the means by which lineal clans maintain themselves. As it happens, there is a biological price to be paid for consanguinity, which is strongly felt particularly in populations where mortality is low.

This study seeks to estimate trends in consanguinity among the Muslim and Druze populations of Israel during the period 1949-1995.

The Israel Population Register is a continuously updated disk record of all current and former citizens. A copy of this record, as of 31 October 1995, was used to construct a file of all Muslim and Druze marriages that had taken place between 1949 and 1995. The marriage records include the given names of the paternal grandfathers of husband and wife. Couples whose grandfathers have the same name may be parallel patrilineal first cousins. A probability algorithm was constructed which provides an estimate, for each name, of how many of these couples are in fact first cousins. The estimates are then summed over all names to provide a population estimate. This procedure was carried out separately by religion, marriage period and region.

Statistically significant declines in consanguinity were found for the Muslim populations of northern Israel, since 1965, and for Jerusalem, since 1949. For the Bedouin of the Negev only a temporary decline was found, for a short time after the reopening of the borders with Gaza, Sinai and the West Bank in 1967. Significant declines in consanguinity were also found for the Druze of northern Israel, after 1982. It is considered, though not demonstrated, that the secular declines are associated with increasing levels of education and urbanization known to have occurred in these populations.