this is the same junk science that was preached against the Irish and blacks a hundred years ago by the Eugenics in UK universities.
What is overlooked: The US (and Australia) is full of the dregs of humanity that the eugenicists wanted to eliminate via birth control.
What happened? Good nutrition increased IQ and height, and people were given a chance to be free, not obey their betters.
Seems to me they eliminated much humanity by bc and abortion but there were still plenty of dregs left. A never ending supply in fact.
Suppose those eugenicists were right. Suppose the welfare class is destroying civilization. One day they’ll all starve but civilization will be dead too.