The difference between a white and black person is the white person has through selective breeding left behind all the monkey type traits we had. If blacks were to do this, they would become white.
Discussion
The Congoids might actually begin to evolve toward our level, given the right circumstances and a lot of time -- as in hundreds of thousands of years. But the real danger is racial mixing, which could set us back 100,000 years, and our mental abilities might not catch up in time before the energy or cosmic-disaster windows close forever on our ability to leave this doomed planet.