In Minnesota Transracial Adoption Study (referred to in my post #41) you had black kids brought up from infancy in white households, in white neighborhoods, white culture -- and it made little difference as far as grown-up IQ and GPA were concerned.
Yeah sure, but obviously you could start to chop around the edges of that, kids who were given up for adoption likely come from parents below the mean, the experience of being an adopted kid (my sister was adopted) itself being different in significant ways, the influence still coming in from the wider society as a kid grows up, etc., etc. It would also be interesting to look at sample size, whether it’s been replicated, etc. Having known a number of black transracial adoptees, my anecdotal experience is certainly that there are substantial differences in average outcomes, whether that has anything to do with differentials in IQ I don’t know.
The average increase in IQ for adopted children is a little over 4%, so that tracks. The difference between 85 and 89 is not statistically significant; however, a 90 IQ is the cutoff for average, so these children are capable of success in society. Adopted children have a much better chance of success than those who are not adopted, regardless of race.
The entire subject of transracial adoption has been infected with identity politics, so empirical data is lacking. Adopted children tend to identify with the parents’ culture and thus is considered a negative outcome by the left. From a colorblind perspective, it is net positive.