This is so punctuated with errors it is hard to know where to begin. To start with, the very definition of eugenics is in error.
It is based on the rudimentary understanding of genetics that began with Gregor Mendel in the 19th Century, combined with the farmer’s knowledge of how to improve plants and animals with selective breeding.
This meant two things: some horrific diseases were actually *inherited* from parents, and if people could figure out how and why, they might avoid having their children so cursed; and, as with farm animals, might it be possible to breed a better person? Smarter, stronger, faster, healthier, etc?
So, for example, in the 1920s, Germans were intensely interested in separated at birth identical twins, to try and find out deductively traits they had in common and traits their learned in their upbringing. Thus started the debate of “nature vs. nurture”, which continues today.
However, on top of this was the dark side of eugenics, that was even more widely embraced: that if you want to breed good people, you have to prevent bad people from breeding.
Almost every western nation embraced some form of this or another. It was just too easy to imagine eliminating from society people who were physically or mentally flawed, generally just sterilizing them so they couldn’t breed.
The latest most blatant example of this was in France, where the health authorities knew that the blood component needed by hemophiliacs was contaminated with HIV, but kept that information secret until almost every hemophiliac in the country was infected and died. Thus in a decade, they eliminated hemophilia from France.
They probably rationalized it as like the elimination of smallpox. “France is better without hemophilia.”
Yet the bottom line is the same for eugenics. That people might someday choose a mate based on their genetics, with the idea that their children will not be afflicted with inherited diseases, and that they might lead better lives.
The transition to confusing ‘eugenic’ farming of crops and domestic animals with ‘farming’ people largely goes back to Ernst Haeckel (1834-1919), the father of German Social Darwinism. His books were widely read on both sides of the Atlantic that helped to fuel the rise of human eugenics. Haeckel was also the very man who coined the term ‘ecology’ in 1866 so that his evolutionary German Social Darwinism also got mixed up with the environmental movement as well. At the heart of the eugenic movement is a confusion of man and nature. Its emphasis upon racism and health comes out of this nature based ethos and paradigm.