Unless you think mind skills/IQ are determined by just 3 or 4 genes you will be very sad at the rate of genomic shift by selective breeding. Elsewhere people are claiming hundreds of genes. That is looking at hundreds of generations to remove the weaker version even assumong you have only a bad dominant version and a good recessive version. One generation to eliminate all the bad dominant copies for one gene. And at the cost of reduced genetic and mental variability which seems likely to reduce population fitness.

however, the current picture of vertabrate development makes it seems like such a simple genetic model for mind skill traits is hopelessly unlikely. You have weird crap like receptors being used for different functions in different areas of the brain. And they migrate / gene activate at different times of development in response to genetic expression partially determined by environmental conditions. Its a big ugly undocumented hack. I tend to assume we are all SWE but if you are not, there is human created code so unmaintainable the cost to fix/understand is easily 10x the cost to create. Evolution i guess has no reason to make it easier on gene engineers. Unless you hope the human brain ends up being kike particle physics with a few elegant math laws that make the apparent complexity simple.