| The ethnic group known as Ashkenazim is
blessed with more than its fair share of talented minds, but is also prone to a
number of serious genetic diseases. Researchers now suggest that intelligence is
closely linked to several illnesses in Ashkenazi Jews, and that the diseases are
the result of natural selection. Ashkenazim are descended from Jewish communities in Germany, Austria, Poland, and Eastern Europe that date back to the 10th century. Today they make up approximately 80 percent of the world's Jewish population. Ashkenazim have the highest average IQ of any ethnic group, scoring 12 to 15 points above the European average. They are also strongly represented in fields and occupations requiring high cognitive ability. For instance, Jews of European ancestry account for 27 percent of U. S. Nobel science prize winners. But the group is also associated with several neurological disorders, including TaySachs, Gaucher's, and Niemann-Pick. Tay-Sachs is a fatal hereditary disease of the central nervous system. Sufferers lack an enzyme needed to break down fatty substances in the brain and nerve cells. Gauchers and Niemann-Pick are similar, often fatal diseases. Because Jews were discriminated against in medieval Europe, they were often driven into professions such as money lending and banking which were looked down upon or forbidden for Christians. Historians suggest that Jews with lucrative jobs often had four, six, or sometimes even eight or nine children. Poorer families, meanwhile, tended to be smaller, possibly because they lived in over hundreds areas in which children were more prone to disease. As a result, the researchers say, over hundreds of years the Jewish population of Europe became more intelligent than their gentle countrymen. But increased intelligence may have come at a cost, with genetic diseases such as Tay-Sachs. Being side effects of genes that facilitate intelligence, researchers argue that highly unlikely that mutated genes responsible for these illnesses could have reached such high levels in Ashkenazim if they were not connected to cognitive performance. While the link is difficult to prove, there is some evidence that Gaucher disease does increase a person's IQ. Around one in three people of working age who were patients of the Gancher Clinic at the Shaare Zedek Medical Centre in Jerusalem had professions requiring an average IQ of more than 120. This group included scientists, academics, physicians, and accountants. Modem-day Ashkenazim are now far more likely to marry outside their ethnic group. A researcher says that he would expect a tendency for both higher IQs and associated genetic disorders to become less marked over time. |