It's polygenic, like height. People who I read in the space of cognitive genomics, such as Steve Hsu and Razib Khan, agree it's looking increasingly plausible. It would require modifying hundreds of alleles. Embryo selection is possible now, just not useful until we have a million genomes tagged with their donors' IQ. 1 of 10 embryo selection give you about 8 IQ points per generation. Hsu thinks Crispr will obsolete embryo selection before it's in wide use.
He also said the following:
>I think there is good evidence that existing genetic variants in the human population (i.e., alleles affecting intelligence that are found today in the collective world population, but not necessarily in a single person) can be combined to produce a phenotype which is far beyond anything yet seen in human history. This would not surprise an animal or plant breeder — experiments on corn, cows, chickens, drosophila, etc. have shifted population means by many standard deviations (e.g., +30 SD in the case of corn).
Or maybe if you put too many IQ-associated alleles in one person you wind up with a psychotic wreck. We don't know how these genes interact, if they do, nor by what mechanism they work. And unlike with corn, you can't just guess until something works; experimenting with actual humans would be a major ethical breach, and there's no animal models of human intelligence. Progress on that front is possible but unlikely in this century.
> Progress on that front is possible but unlikely in this century.
I agree in a way, but every time this comes up I point out that in East Germany they would have pounced on this technique and built a secret base in the wilderness to work on it. I say East Germany because it is a matter of historical record, what they put their athletes through.
So I'm saying that progress on that front is possible but unlikely in this country, where we consider a major ethical breach to be something to be avoided entirely, not just hidden.
You're talking about a country which prepared to biowarfare by dropping bacteria on its own civilian population (including San Francisco Bay Area[0]) to see what happens, without telling anyone. A country that has its own movie industry creating story after story of its military experimenting on people, to the point it's pretty much became a trope.
So no, I wouldn't be so sure this couldn't in principle happen in the US of A.
He also said the following:
>I think there is good evidence that existing genetic variants in the human population (i.e., alleles affecting intelligence that are found today in the collective world population, but not necessarily in a single person) can be combined to produce a phenotype which is far beyond anything yet seen in human history. This would not surprise an animal or plant breeder — experiments on corn, cows, chickens, drosophila, etc. have shifted population means by many standard deviations (e.g., +30 SD in the case of corn).