Do genetic disorders actually make Ashkenazic Jews smarter?

Genetic diseases prevalent among Ashkenazic Jews (of European descent) may actually be tied to a higher intellience quotient, according to two American professors.

Anthropology researches Gregory Cochran and Henry Harpending argue that neurological disorders such as Tay-Sachs and Canavan disease have made Jews smarter, due to what is known as heterozygote advantage.

The condition of having one copy of a mutated gene can present a health benefit, they say, whereas having two can be deadly.

The controversial theory was first presented in professors their book," The 10,000 Year Explosion", released in February.

The Baltimore Sun quotes the professors as citing sickle cell anemia, common amongst people of African descent, where two mutated hemoglobin B genes distort red blood cells until they cannot carry oxygen to internal organs.

On the other hand, people of African descent who have only one mutated hemoglobin B gene develop a resistance to malaria.

Under Cochran and Harpending's theory, natural selection would favor those Jews who only formed the single mutated gene, which has the potential to lead to greater brain power, according to a recent article in the Baltimore Sun.

The theory could stir uncomfortable memories of race-based theories of intelligence, and some researchers have said it fails to take into account social and cultural factors that may affect how intelligence is gauged in different ethnic groups.