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If U.S. whites have an average IQ of 100, and U.S. blacks have an average IQ of 85 (one standard deviation less,) then one half of U.S. whites will have at least average intelligence, whereas only one sixth of U.S. blacks will. About one sixth of U.S. whites will have fairly high intelligence (IQ of 115 or higher,) but only one out of 20 U.S. blacks will. About one out of 20 U.S. whites will have quite high intelligence (IQ of 130 or higher,) whereas well below 1% of U.S. blacks will.

I looked up a table on normal distributions, so I need to correct those last figures, as I was confusing location at either end of the bell-shaped curve with location at one end of it. IQ of 100 or above represents above the average for whites, one standard deviation above the average for blacks: this is 50% of whites, 16% of blacks. IQ of 115 or above represents one standard deviation above the average for whites, two standard deviations for blacks: this is 16% of whites, and 2.3% of blacks. IQ of 130 represents two standard deviations above the average for whites, three standard deviations for blacks: this is 2.3% of whites, 0.13% of blacks.