Intelligence is more based on cultural and environmental factors, not racial. In all situations being equal testing scenarios, you don’t see the standard deviation that you do if you pull those with diverse environmental backgrounds.
Sorry, but that is utter nonsense. The one standard deviation difference between white and black populations in the U.S. is one of the most consistent findings in psychometrics.
How much of this is genetic and how much is environmental is of course a subject of considerable debate. I think 50/50 is as good an estimate as any.
The deviation would be slightly smaller if given the same environment, but it still exists, and always will. For example, whilst the average African has an IQ of around 70 (Average White American = 101, average Japanese = 110), the average Black American has an IQ of around 85. Still one full standard deviation below the White American (with whom they were raised in the same society) average.