For any trait to become powerful enough to permeate the whole species it has to convey the individuals that possess it the ability to pass their genes (and the trait) to their offspring in greater sucess and quantity than those who don’t have it. In other words, it must increase the ability to survive. Back in Darwin times, only 50% of humans in England survided to age 21 (an age in which they can reproduce and spread their genes). You could conceive some traits that would move this population to evolve, for instance, resistance to cholera or chicken pox; but now that medical and healthcare practices allow 99% plus of English babies to reach sexual maturity, EVERY TRAIT is passed on. In today’s world there are not real “bad “genetic changes that would resuce your chances of passing your genes. Also, those humans that could be considered to be more “apt” or “fittest” or “successful” in today’s standards are not going to necessarily have more offspring because of that reason. In fact, probably the opposite is true!
So humans will change over time, but not necessarily according to any “improved” model.

Under which circumstances, for instance, would the IQ of H. sapiens increase over time? Evolutionarily speaking, only under conditions in which higher IQ males mated preferably with higher IQ females AND had more children than the average. Is that occurring?

The answer is NO! Probably the opposite is more frequent.

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