> [...] Children that grow up in high income families have better IQ results than children living in poverty.
Yes, because high IQ parents tend to make more money and tend to get high IQ children (even if those children got adopted away or orphaned early on). On the other hand, if high income families adopt children of low IQ parents those children end up with an IQ resembling that of their low IQ biological parents.
>>even if those children got adopted away or orphaned early on
Was race accounted for. i.e. Where there minorities and white kids in the group. If only white kids then that tells me that the problem is more systemic. i.e. racism.
By the way, I don't know if you have heard about these two papers before. They might interest you (or not).
Hopkins, Russell, Schaeffer, "Chimpanzee Intelligence is Heritable", Current Biology, 2014.
<way too many coauthors to list but the main guy seems to be P.M. Visscher>, "Genome-wide association studies establish that human intelligence is highly heritable and polygenic", Molecular Psychiatry, 2011.
The latter paper reports on a study (with N=3511) on unrelated people to see whether their genotype and their phenotype regarding intelligence had anything to do with each other. People were tested with DNA chip for SNPs and had their IQ measured. The interesting result was that people who had more similar DNA also had more similar IQs (and vice versa, of course).
Yes, because high IQ parents tend to make more money and tend to get high IQ children (even if those children got adopted away or orphaned early on). On the other hand, if high income families adopt children of low IQ parents those children end up with an IQ resembling that of their low IQ biological parents.
The research has been done.