The Evolution of Human Genome Selection

There clearly are some genotypes out there which are beyond what we've seen and that's familiar to every agricultural breeder who's ever bred sheep dogs cows corn you name it they can always take the domestic thing and if they want they can push it in a direction which is better than any wild type that's ever lived. I think this similar story is going to apply with humans well how difficult do you think it will be to increase human intelligence?