Who first measured intelligence and History of Intelligence Testing

How did we come up with a way to measure intelligence?
He suggested that our smarts have a lot to do with heredity, so if we encouraged smart people to breed with each other, we could essentially create a master race of geniuses. If that sounds a litte sketchy, it's  because it was like, really sketchy !
Many of these kids had never been in a classroom and teachers wanted to figure out they could identify kids who needed extra help. Enter Alfred Binet and Theodore Simon, two French psychologist who were commissioned to develop a test to measure a child's so-called mental age.
The concept of a kid's mental age is essentially the lever of performance associated a certain chronological age.
Alfred Binet believed that his tests could measure a child's current mental abilities, but that intelligence wasn't a fixed, in born thing.
In other words, he was no eugenicist. He was hoping that his tests would improve children's education by identifying those who needed extra attention.
But Binet also feared that these tests would, in the wrong hands, be used to do just the opposite: labeling children as "lost causes", limiting their opportunities.
And now, was he on to something because that is pretty much exactly what happened.

German psychologist Wiliam Stern used revisions of Binet and Simon's work to create the famous intelligence quotient or IQ measurement. At the time, your IQ was simply your mental age, divided by your chronological age, multiplied by a hundered.
So for exanple Bruno is six and so is his mental age, so his IQ ranks at a hundred, but his little sister Betty is a four year-old with a mental age of five, so her IQ would be 125.
That formula works pretty well for measuring kids but it falls apart when it comes to adults who don't hit measurable developmental steps like kids do. I mean there's no real difference between a mental age of 34 and 35. But stanford professor Lewis Terman started promoting the widespread use of intelligence testing in early 1900s and with his help the US government began the world's first massive ministration of intelligence tests, when it assessed World War I army recruits and immogrants fresh off the boat.
Unlike Binet, Terman did use these numerical findings as a kind of label and he throught his tests could, as he put it: "ultimately result in curtailing the reproduction of feeble-mindedness".
This kind of testing played right into eugenicist' sensibilities and soon the eugenicist movement in the US had a pretty good fanclub raising money from the Carnegie's and Rockafeller's and with proponents working at Harverd and Columbia and Cornell.

In the first half of the 21st century, intelligence tests were used to enforce the sterilization about 60,000 people, around a third of whom were in California. Most were poor white women, often unwed mothers or prostitutes. Other eugenics efforts persisted later into the century and there is evidence of poor African American, Native American or Latina women being forcibly or covertly sterilized in large numbers as recently as the 1970s.
Hitler and his cronies took the idea of intelligence testing to even darker conclusions.
The nazis were all about selecting against so-called "feeble-mindedness" and other undesirable traits as they sought to strengthen what they saw as their Aryan nation.
They sterilized or simply executed hundreds of thousands of victims based of their answers tto IQ test questions that were really more abut adhering to social norms than measuring actual intelligence. Question like: "Who was Bismarck?" and "What does Christmas signify?" So you can see how this terrifying history still makes some people leery of how such test are administered, interpreted and weighted.

Today we understand that intelligence, as defined by all the people we've talked about here, does appear to be a real and measurable phenomenon.
But no one can say that they've disentangled all of the would-be genetic, environmental, educational and socio-economic components of it.
You also learned about the history and methods of intelligence testing, IQ score and how eugenics turned to the dark side and has since made even talking about intelligence kind of controversial.