>>11795242Jensen, in his 1998 The g Factor, supplies the formula (d/?1-h2) where d is the size of the mean difference in some trait in terms of Cohen’s d and h2 is the narrow-sense heritability of a trait. If groups display a 1 d difference in some trait that’s 50% heritable, the environment must be 1.41 d worse on average in the group with the lower mean level of the trait in question. For the black-white gap in intelligence, which Turkheimer is most focused on, the difference in the US is 1.1 d and the latent heritability has been found to reliably turn out greater than 85% in adulthood. Assuming the naïvely corrected heritability from Panizzon et al. (2014) of 91%, and assuming that both races show the same heritability, the necessary environmental gap is 3.67 d. This means that black environments meet the white mean environmental quality less than 1% of 1% of the time. Given that socioeconomic status measures index environmental quality and the gap in datasets like the NLSY, NELS, NSID, NCPP, and various test standardization samples are usually around 0.65 d, this suggestion is simply incredible.
Hmm?
