Consanguineous marriages have been practiced since the early existence of modern humans. Until now consanguinity is widely practiced in several global communities with variable rates depending on religion, culture, and geography. Arab populations have a long tradition of consanguinity due to socio-cultural factors. Many Arab countries display some of the highest rates of consanguineous marriages in the world, and specifically first cousin marriages which may reach 25-30% of all marriages. In some countries like Qatar, Yemen, and UAE, consanguinity rates are increasing in the current generation. Research among Arabs and worldwide has indicated that consanguinity could have an effect on some reproductive health parameters such as postnatal mortality and rates of congenital malformations. The association of consanguinity with other reproductive health parameters, such as fertility and fetal wastage, is controversial. The main impact of consanguinity, however, is an increase in the rate of homozygotes for autosomal recessive genetic disorders. Worldwide, known dominant disorders are more numerous than known recessive disorders. However, data on genetic disorders in Arab populations as extracted from the Catalogue of Transmission Genetics in Arabs (CTGA) database indicate a relative abundance of recessive disorders in the region that is clearly associated with the practice of consanguinity....
Another study shows that the risk of having an IQ lower than 70 goes up 400 percent from 1.2 percent in children from normal parents to 6.2 percent in inbred children: "The data indicate that the risk for mental retardation in matings of normal parents increases from 0.012 with random matings to 0.062 for first-cousin parentage." (Proceedings of the National Academy of Science, 1978 Effect of inbreeding on IQ and mental retardation"). The study A study of possible deleterious effects of consanguinity concludes, that "The occurrence of malignancies, congenital abnormalities, mental retardation and physical handicap was significantly higher in offspring of consanguineous than non-consanguineous marriages."I am sure that this has nothing to do with the culture of that part of the world.
And of course, those who support laws against incest are just nasty bigots.
To my surprise bans on first cousin marriages in the U.S. are pretty recent with some websites claiming it was prejudice against the poor and immigrants, and denying that increased rates of birth defects are pretty irrelevant: "the increased risk of spina bifida and cystic fibrosis at only 1.7% -2.8% higher than for children of unrelated parents." Yup, what if your kids end up with those problems? Bigots. Does cognatamatrimonia phobia have a nice ring? From cognata, Latin for cousin, and matrimonium, Latin for marriage.
So... If we bring them to areas with incest laws, their brains will improve.
ReplyDeleteIt may take more than one generation. Don't hold your breath.