Quote:Provo, UT, Jun. 3 (UPI) -- A University of Utah study of Ashkenazi Jews suggests an unusual link between their genetic diseases and their higher intellectual ability.

The study, to appear in Cambridge University's Journal of Biosocial Science, says this unusual pattern of diseases among the Ashkenazis of central and northern Europe is the result of natural selection for enhanced intellectual ability.

The study says the selective force was the restriction of Ashkenazim in medieval Europe to occupations that required more than usual mental agility, the New York Times reported Friday.

The study has received mixed reaction, with some scientists saying the finding is extremely implausible. Others say the researchers have made an interesting case.

The Utah researchers say Ashkenazic diseases like Tay-Sachs are a side effect of genes that promote intelligence. They say for some 900 years Jews in Europe were restricted to managerial occupations, which were intellectually demanding.

In the United States, Ashkenazi Jews make up 3 percent of the American population but have won 27 percent of its Nobel prizes. They also account for more than half of world chess champions.