You can easily add genes to the junk DNA sections of us.
I'm sorry. I really, really hate the phrase 'junk DNA' because everyone assumes it means "this bit isn't for anything".
It doesn't.
It means "we don't have a bloody clue what this bit does"
http://en.wikipedia.org/wiki/Junk_dna(I admit that 'nothing' is still a possibility for any given bit of DNA, but we don't know)
Call me paranoid, but I do not wish to attempt to modify or 'improve' a potentially critical system when I don't know how it works in the first place. I leave that to the staff of PC world....
Which, fundamentally, is why I think eugenics is a bad idea. We do not know how genetics functions - not on a deep enough level to manipulate it with a will.
Intelligence is a hard-enough to measure subject anyway, but as noted above, all evidence suggests that a genetic connection is tenuous at best. Certainly innate intelligence is secondary to eductation and upbringing. If you train someone from age 6-7 they will be a decent surgeon.
Unless they suffer from involuntary muscular spasms, I don't care where you got them from. They may not be superb but they will be good enough to qualify.
More to the point, voluntarily removing genetic traits from the gene pool forcibly (i.e. not via the evolutionary process) involves removing ALL traits attached to such a genetic pool. That's disease immunity, genetic diversity providing protection from recessive traits, and several things we haven't found yet.
Improving access to birth control is a good idea; not for genetic reasons but because if you improve healthcare to a poor country where people traditionally have large families (because they traditionally have shorter lifespans, more labour intensive incomes and lousy mortality rates), you get a catastrophic population growth rate.
Look at China's urbanisation rate and you'll see what I mean.
http://news.bbc.co.uk/1/shared/spl/hi/in_depth/china_modern/html/2.stmThe massive increase of population amongst
poorer families (not any less intelligent) is a far more real threat to the "misery quotient."