"Cochran and Harpending also cite studies claiming that Ashkenazim have the highest IQ of any ethnic group for which there’s reliable data, perhaps as much as a full standard deviation above the general European average, which means, at the far end of the spectrum, that 23 per thousand Ashkenazim have an IQ over 140, as opposed to 4 per thousand Northern Europeans."
"Cochran and Harpending also cite studies claiming that Ashkenazim have the highest IQ of any ethnic group for which there’s reliable data, perhaps as much as a full standard deviation above the general European average, which means, at the far end of the spectrum, that 23 per thousand Ashkenazim have an IQ over 140, as opposed to 4 per thousand Northern Europeans."