Worth the 20 minute watch

Charles Murray's IQ Revolution (mini-doc)

https://www.youtube.com/watch?v=7_j9KUNEvXY&t=52s&pp=ygUfQ2hhcmxlcyBNdXJyYXkncyBJUSBSZXZvbHV0aW9uIA%3D%3D