Steve Sailer reports that Black females have IQ’s 2.4 points higher than Black males. He discovered this after analyzing Charles Murray’s Armed Forces Qualification Test data for 1997. The same data also showed that White women scored 0.8 points higher than White men.
Assuming this is correct then, if we put US Black IQ at 86 (somewhat controversial):
IQ score Black males 85.75 Black females 87.25 Black total 86 Black M-F difference 2.4
This finding has been known for some time. Thomas Sowell reports that among Blacks with an IQ over 140, females outnumber males 5-1. Richard Nisbett reports that Black females are twice as likely to have IQ’s over 120 than Black males are.
It is hard to fathom a genetic reason why this gender difference might exist or even an environmental one for that matter.
Nisbett, Richard E. 2009. Intelligence and How to Get It: Why Schools and Cultures Count. W.W. Norton