I still find it hard to believe that if you took different race and economic backgrounds of kids maybe aged 2 or younger, there would be much difference in IQ…
The young age of 6 would start having differences due to economic impact (like most wealthy kids with a stay at home mom or people who can afford preschool) would obviously do better on IQ or other tests because they have had this interaction or game before, but I have strong doubts that given the same pre-school opportunity, someone of a certain color/race/parent with lower IQ will score lower than someone else.
Is there a study stating this? Again, I am removing poor economic environments where the young kid may worry about being shot daily and be malnurished vs hereditary IQ genes being passed to the next guy…