Assuming that you were a despot, could you create a population that had an unusually high average IQ, higher than any extant population? Sure. It’s trivially easy. There may be other ways, but old-fashioned truncation selection should do the trick. Come to think of it, Warren Buffet could probably manage it just by bribing people on a certain list to marry each other – like the Howard Foundation.
Most university educated types would, if asked, say that this is impossible, particularly if you called it eugenics. That’s my guess, anyhow. Some of my colleagues think that most people really know the score (understand heritability of intelligence) and are just saying what they think society wants them to say, but I suspect that the vast majority really don’t know. Ignorance is the default state.
The truth is somewhere in between. People are ignorant of this, but it’s not mere ignorance. Everyone knows about dog-breeding, and everyone knows that intelligence is one of the the things certain dogs are bred for. Ignorance about the human case is in a sense deliberate (though not exactly conscious). And the reason is obvious: once you accept that people can be bred for intelligence, it’s harder to resist the thought that people have been bred for intelligence.