I expect the SD to be much higher in the real world, as anybody who has observed real children and their parents, for example a teacher, can attest. When you ad

I expect the SD to be much higher in the real world, as anybody who has observed real children and their parents, for example a teacher, can attest. When you add environmental and cultural factors, as well as other genetic traits that strongly correlate with social success, such as agression, physical attractivity and verbal skills, it's pretty much a coin toss. What we know for sure from educational studies is that early intervention at the 2-6 years of age can completely negate any "inherited" learning issues, be they genetic or culturally acquired via parental neglect. So maybe that's where the focus should be. You also have to ask how much sense does the premise hold. How do you exactly determine which allele relates to inheritable intelligence? It seems almost impossible to separate and control for social factors, i.e. to actually find the that the genetic markup of white upper-middle class people is the best predictor of "intelligence", because there is no definition of intelligence that this group is not better trained and better socially positioned to exhibit. This fundamental difficulty in defining a culturally neutral measure of intelligence (and it's pervasive tendency to produce racist outcomes) has pushed the field into disrepute and makes people attack its conclusions.