You are not right to say something like this.
If you want to compare people, they must have the same basis, it means the same life, education, experience etc.
If not, it's natural that person who is more educate, experienced etc. will have better results in any research about such subject.
If you replace white and black child, and white child send to Africa, and black to America, who will be smarter than?
What do you think?
If you give them equal opportunity, you will find out that blacks are intelligent and smart as any white man.