I don't think you even need to think of it on the level of genes (because most of the time, chromosomes are inherited whole (barring crossing over)). So you'd

I don't think you even need to think of it on the level of genes (because most of the time, chromosomes are inherited whole (barring crossing over)). So you'd just be picking the best combinations of random selection of chromosomes contributed by the parents. It's like being able to roll 100 times and picking the best one in D&D character creation. The improvement might not be able to be done infinitely, but could at least get us to everyone having IQ 130, which would mean a reduction in all the problems associated with lower IQ. (Crime, poverty, lack of educational achievement, bad health) i.e. a father has two variants of chromosome 6, one good and one great. Why not make sure that his kids just "by chance" get the great one? There will be lots of tradeoffs, but it'd always be better to occasionally step in and make a choice than to always accept randomness.