Good DNA and Genetics in the brain area can get you between 1 and in rare cases 2 standard deviations right with minimal help. Likewise ideal help in the educational area, best tutors, stoic father to make you strong, wealth and 19 years of top recognized education, is good for buying a standard deviation right of median but it's no silver bullet.
https://www.youtube.com/watch?v=7HRmfIEWtyo

Now that the operating principles of the brain have escaped into digital world, and intelligence can be mechanically separated from data in exchange for solar mass quantities of energy, over the next thousand years the "self" and core of thinking is going to slowly migrate into bio-neural gelpacks, everyone has one in their pocket and maybe a big one in a backpack. And there's one in every house and a bigger one on every street corner, and bigger still at the central office, and the biggest one at the nest of the dominant polyergus formica that has its own nuclear reactor to power it.

It can be increased in software, so by definition, it can be increased in biology too, it's just hard, because education isn't a silver bullet, it just shows you the door.

DNA and Genes are the greater portion of IQ, in the way people meant to mean it, if you want to get to that coveted 2 sigma right.

It's also no gravy train either, since people hate intelligence in others.