I believe there is measurable mate-selection preference between the profoundly stupid and the moderately intelligent, but in regards to mate-selection I believe that the average male is intelligent 'enough.' Additionally, it's only been fairly recent (in terms of human history) that hyper-intelligence has translated to much greater wealth than the moderately intelligent. A moderately intelligent hunter/gatherer could produce as much food and acquire as much wealth as a hyper intelligent hunter/gatherer. Neither the (hypothetical) hyper-intelligent hunter/gatherer nor his off spring gained any reproductive edge from the increase in intelligence.
I guess what I'm trying to say is that there haven't been enough generations of humans, during which hyper-intelligence would make a reproductive difference, for selection to occur and make an impact on the gene pool. The fact is that the opportunity for this type of selection to occur is passed: we pay the least capable among us to reproduce, which in turn causes the capable to have fewer children due to the lack of resources (taxes for socialism). Sure, it's possible that we may witness an increase in the number of geniuses but they'll be swamped by the moderate and low intelligent.
A more intelligent human can out hunt, out trade, out farm, out fight and out plan a less intelligent human of otherwise equal ability.
Intelligence has always been correlated with wealth, for as long as there has been wealth. Every human invention and innovation has as its author - a highly successful and intelligent individual. The inventor of the spear thrower - as just one example - no doubt had great reproductive success.
There have been at least 100,000 years worth of human generations of fully modern humans - plenty of time for a gene for greater intelligence that had no associated drawback to be favored.
My point is that almost everything has a drawback - there is no such thing as a free lunch.
As far as socialism encouraging layabouts to reproduce - thankfully that is a very recent ‘innovation’ and a symptom of how little scarcity of resources is a problem in the modern industrialized world.