Thus, immigrants at Ellis Island were tested using the Binet scale (which was never meant for adults) so that eugenicists could rank races of people like they were Pokemon, but without acknowledging that they could level up with experience. The "results" naturally showed that intelligence was closely linked to how white your skin was, which was then used to propagate the idea that people from southern and eastern Europe were barely smarter than well-trained horses, and about as useful.
National Parks Service
"How good are you at pulling carts?"
It went even further downhill after Binet's invention was used to mess with people's junk. After intelligence tests took off, 30 states used them as the basis of forced sterilization, which by the 1960s affected 60,000 Americans, all because an old-timey BuzzFeed quiz determined that their Simpsons character was Ralph Wiggum.
Binet died in 1911, thankfully missing the worst of this. But not long before his death, he complained about the "brutal pessimism" of "deplorable verdicts that affirm that the intelligence of an individual is a fixed quantity." And if he wasn't such a gentleman, he probably would have added "you unbelievable assholes" to it.