The first lobotomies were performed in 1935. 

Two American neuroscientists removed brain tissue from the frontal lobes of chimpanzees, noting that one of the primates became less agitated following the procedure. That same year, a Portuguese surgeon performed the world’s first lobotomy on a human. He would later receive the Nobel Prize.

This experimental surgery was said to reduce aggression, disorientation, and even violence in severely mentally ill patients. It was, of course, a frightening prospect to have someone drill a quarter-sized hole in one’s skull, insert a tiny wire, and sever the connection between one’s prefrontal cortex and the rest of one’s brain. Even in the early 20th century, doctors recognized the frontal lobe’s importance in accessing imagination, discernment, and self-esteem. But severing these essential aspects of personality was considered a small price for pacifying the unpacifiable. Some 50,000 people were given lobotomies between 1949 and 1952 alone.