Murder rates, regardless of the availability and use of guns, are strikingly consistent by racial group worldwide.
That’s very much the same as educational test results. E.g., American whites are no more murderous than whites worldwide, and American Chinese/Korean/Japanese kids score on achievement tests in the range of their counterparts worldwide.
Derbyshire was thrown-out of The National Review recently for suggesting that there is a big difference in the innate abilities among the different racial groups in the U.S. Even discussing urban problems results in being punished or branded a racist.