Intelligence at least as measured by IQ tests is not distributed evenly across humanity. Intelligence as measured by scientific achievements is also not distributed evenly across humanity. Now, this does not mean that intelligence is necessarily not distributed evenly across humanity. For example, I imagine that Germans in 1 AD probably had about the same innate biological intelligence level as Germans in 1800. Yet Germans in 1 AD had few intellectual achievements, whereas in 1800 were some of the most intellectually achieving people in the world. So clearly there is more going on than just biologically innate intelligence. Yet certainly there is some good reason to believe that some human groups have more innate biological intelligence potential than others. I don't think it's racism to claim this. It would be racism to advocate, for example, for treating a high-performing person like a low-performing person because he comes from a low-performing ethnic group. Which I'm not. Like I said in another comment, my attitude to illegal immigration is neutral. But from the point of view of what is best for the United States as a country, which is different from what I personally want, I think it's probably best to encourage immigration of average-high-intelligence groups rather than average-low-intelligence ones.