I would much prefer to believe in the standard model of human intelligence, which is that there is no inherent difference between ethnic groups.
Unfortunately, this particular lovely model appears to have been murdered by a gang of brutal facts.
What we have here is many thousands of brilliant researchers trying desperately for at least five decades to find some way of measuring intelligence that will demonstrate the standard model to be true. I suspect whoever did so would win a Nobel Prize, or at minimum the plaudits of all his colleagues. Which they all know.
So either all these researchers are unable to find the appropriate metric. Or it doesn’t exist.
Tsk. It's in the same drawer as the Gay Gene.