Regarding inbreeding, I happen to have met some people who did this. They felt they couldn't not do it since it would lead to their children deteriorating to average people. The kids end up being very homogenous to the parents but there is something strikingly different with the kids who are second generation inbred. The only reason they made it in life was because they inherited wealth and job positions. I can't find the word for this but theyre very closed minded and have a warped view of the world, unique to themselves. As much as you'd think their world view is off, they think of you and your world view. I'd bet that if they inbred again they'd get kids with mental development issues.
Regarding breeding, it's hard to convince people to marry and have kids purely on the basis of their genes. There is another way though and the research is close to done. Its called cognitive genomics. This is possible through extracting several eggs from a woman and fertilizing them in vitro with the mans sperms. Then the embryos genes are analyzed and the embryo with the genes you want is put back into the woman and becomes a baby. If everyone did this then for every generation kids would have 5-15 IQ points more.
Regarding breeding, it's hard to convince people to marry and have kids purely on the basis of their genes. There is another way though and the research is close to done. Its called cognitive genomics. This is possible through extracting several eggs from a woman and fertilizing them in vitro with the mans sperms. Then the embryos genes are analyzed and the embryo with the genes you want is put back into the woman and becomes a baby. If everyone did this then for every generation kids would have 5-15 IQ points more.