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Archive for the ‘Ashkenazi’ Category

Albert Einstein is reputed to have said that  “Things should be descr ibed as simply as possible, but no simpler.” The same principle must be invoked  in explaining  Einstein himself. We evaluate the hypothesis that the  high intelligence  test scores observed in the Ashkenazi  Jewish population are  a consequence of their occupation  of a social niche over the last millennium that selected strongly for IQ. We summarize  the evidence of high intelligence test scores  in this population, approximately one standard deviation higher than the  northwestern Eur opean average, and then the relevant social  history. We suggest that there was an increase in the frequency of  particular genes  that elevated  IQ as a  byproduct of this selective regime, which led to an increased incidence of her editary disorders.

There ar e several key observations that motivate our  hypothesis. The  first is that the Ashkenazi  Jews have  the highest average IQ of any ethnic group, combined with an  unusual cognitive profile, while no similar elevation of intelligence was observed among Jews in classical times nor  is  one seen in Sephardic and Oriental Jews today.

The second is that the Ashkenazim experienced  very low inward gene  ow, which created a favor able  situation for natural selection.The third  is  that they experienced unusual selective pressures that were likely to have favored incr eased intelligence. For the most part they had jobs in which increased IQ strongly f avored economic success,  in contrast with other populations, who were mostly peasant farmers. They lived  in cir cumstances  in which economic success  led to incr eased reproductive success.

The fourth is the existence of  the Ashkenazi sphingolipid, DNA  repair, and other  disease clusters,  groups of biochemically r elated mutations that  could not  plausibly  have reached their present high frequencies by  chance, that are not  common in adjacent populations, and that  have physiological effects that could  increase  intelligence.