If whatever genetic feature that has made someone more intelligent didn't come with downsides, then we would expect it to be more prevalent in the population.
Excepting any that have only recently arisen, but I'd assume those to be rare.
Excepting any that have only recently arisen, but I'd assume those to be rare.
Recommended reading: The Marching Morons by Cyril Kornbluth https://en.wikipedia.org/wiki/The_Marching_Morons
Never heard of that book and from the wiki entry it sounds amazing and hopefully not prescient.