But these are not facts, even though the interpretation of the data matches your prejudices.
The "Heaton norms" are based on the socio-economic norms in a relatively small black population in San Diego. They do not take into account the differences in upbringing and advantages that more white people tend to have over black Americans. The NFL has taken this study and using it far beyond it's intended use, using it to prejudicially disadvantage black players simply based on "typical" results, using skin color, from a weak study.
I worked for a private school more than nearly 30 years ago, where most families had every financial advantage -- a very significant number of them were from millionaire families, and several from billionaire families (seriously). The tuition back in those days was about $30,000 a year for grade school students, not to mention thousands more for books, devices, and travel. Students had tutors, training for SAT/ACT tests, and highly personalized counseling to find student strengths and improve student weaknesses. A significant number of students had servants at home to handle all responsibilities, and students didn't need jobs to make ends meet or have plenty of spending money. For what it's worth, most of the students tended to be white or Asian, but the school also had a number of "scholarship" students who were brought in for ethnic diversity. They came from a background without many of those advantages, but when they were able to use the resources and assistance of the school, they excelled as well.
That's an extreme example, but the foolish idea that the level of melanin in one's skin is a general indicator of cognitive ability (note the spelling), is ridiculous.