We believed we’re a complete product of our genetics, and invented eugenics
According to Garland Allan, a biology professor at Washington University in St. Louis, when we started talking about biological determinism in the 18th century, it promoted the idea that we inherited everything we are from our parents. Beyond height and hair color, proponents believed personality, criminal tendencies, and even laziness had more to do with our genetics than our environment or other external forces. It’s a dangerous way to think, and by the late 1800s naturalist Francis Galton was talking about eugenics and selective breeding as a way to encourage the inheritance of good traits and ultimately, the creation of a more perfect race of humans. You can see where this is going.
Galton published Hereditary Genius in 1869, preaching that smart people were biologically superior to the world’s slackers. According to genetics writer David Shenk, the world didn’t look back.
The Third Reich had one of the most notorious eugenics programs, but other countries did it, too. The U.S. introduced sterilization legislation in the 1920s and more than half the states established their own involuntary programs. They were largely based on IQ tests that ranked people on a scale from (not making this up) “normal to high-grade moron.” It wasn’t until the 1970s the public found out thousands of people had been sterilized, all in the name of a bogus scientific theory (via Britannica).