>>12604461P3
Because different subtests are more G loaded then others, thus more genetically determined. (pic related is the WAIS-IV, ranging from 80% to 25%) If the differences in performance are because of environmental differences, you would see significant performance differences in the 25% subtests, and only a slight performance drop in the 80% subtests. Alternatively, differences in genetics would warrant differences in the 80%, and not so much the 25%. Because Africans in Africa do worse in all subtests ubiquitously their decrease performance can be attributed for both genetic and heritable. (thus does not just apply the WAIS-IV, which is pic rel, but other culturally fair tests, Forwards digit span [how many numbers you can remember, which also has a heritability of 0 and can be improved if you practise], vs backwards digit span [how many numbers you can remember then repeat backwards, which is also cannot be permanently improved if you try to, studies have tested this] is a noteworthy example where backwards digit span, the harder more g loaded version of essentially the same task, is the more genetically innate test. A lot of published research has identified race differences in score performance to be most significant on the Backwards Digit Span tests)
Furthermore, adopted children are reported to have higher IQ’s then they should be genetically predisposed to have. However, they ONLY do better in the environmental components of IQ tests, as in they do slightly better in the 0.8 g loaded tests, and significantly better in the lower 0.2-0.4 g loaded tests. The correlation between g loading, and increased performance is, I kid you not -1.0. (study titled: Are adoption gains on the g factor? A meta-analysis). This is analogous to Person C, in the second scenario that can be determined to be shorter for genetic reasons, despite sharing the same environment.
see pic rel for
>>12604461 