Technology

It is not genetic, USA is not an old enough country to have had any significant genetic evolution.
It is instead as Richard Dawkins has described Memetic.
Americans have a tradition of being extremely proud of being free, this feature has been advertised as the most significant thing about USA to Americans to a degree that is akin to brainwashing.
While freedom admittedly is a good thing, the way Americans praise it religiously has turned out to be toxic.
Because sociopathy is now seen as the ultimate expression of individual freedom, so sociopathy is widely admired as a virtue.
This combined with how sociopathy is often rewarded economically, because exploiting people and grabbing all the money for yourself is considered being smart, and the #2 thing religiously praised in USA is money that also reward sociopathic behavior.

This is all about social standards, and the values of society, and has nothing to do with evolutionary shortcomings.
That said, the way some people here claim you are pushing eugenics is completely baseless.

But contrary to your thinking, it seems to me that evolution favor the intelligent more now than it ever did. The demands to intelligence to do well in society are ever increasing, and doing well is an advantage when wanting to have children.