From my observations, about 3/4's of the black population are way below average intelligence and extremely immature, and the other 1/4th are somewhat embarrassed of this.
By the way, to those who say there are a lot of above-average intelligence black people..... if this is true, why can't any of them get passing grades on college entrance exams when affirmative action is removed? Not even one.
"Intelligence" is not always easy to measure and there are different forms of intelligence. Just because you haven't had the chance to go to college doesn't mean you are not intelligent and, conversely, a degree is not always proof of "intelligence". Every year there are a lot of students who graduate and who are unable to think by themselves and to have judgment. It's not just students, by the way. A good number of academics show surprisingly poor judgment and reflexion capabilities, especially when it comes to political issues...
But let's assume that it is simple to measure intelligence and that there is a strong positive correlation between "intelligence" and the level of your college degree. The fact that a given part of the population is less likely to go to college does not necessarily mean that it is because these people are less "intelligent". I am not going to insult YOUR intelligence by elaborating on this, am I ? There are social factors that individuals do not control and that determine to a certain extent their chances of success or failure.
Lastly, while your observation about passing grades on college entrance exams might be true in the US (although I suspect that "not even one" is exagerrated), I can tell you that it is not true in Europe. I live there and I happen to be a professor of mathematics, so I am in a good position to have an opinion. Just to mention my personal experience this year, my best MSc student has African ancestry, and in another graduate course I give I have an African student who is very sharp and who is anything but stupid. Put an individual in the right environment, teach them good principles and show a good example to them, and they will likely do well too.