It was long understood that Mercury and Lead caused madness and dullness of mind, but the masses were highly aware of such toxins and regularly elected officials who fought against the spread of such contaminants, with respect to Thomas Midgley Jr. who imbued gasoline with lead for the sake of "preventing engine-knock in the internal combustion engine," brilliant! It created a generation of highly productive subservient workers who built the biggest economy in the world. It wasn't until 1986 that Lead was banned from gasoline.
Still, back in early post-war America, at the behest of Ivy League academics, the U.S. Government was subsidizing extremely unethical research in the control of human behavior. Experiments on human behavior conducted at Ivy League Universities where the data was kept highly proprietary was only recently exposed by Rebecca Lemov in her book "World As Laboratory: Experiments with Mice Mazes and Men."
Yet another field was coming into focus that might provide a more permanent solution to dissidence and non-compliance: Virology. The human genome had not yet been discovered, but scientists were following a hot lead: Diseases of the brain that inhibited defiance, caused by viral infections.
In 1947, an infection was discovered in Uganda that inhibited the growth of the human brain. It was isolated by none other than scientists working for the Rockefeller Foundation. Now it's available for sale. Not necessary anymore since it's quickly being spread by Mosquitoes and sexual activity.