In 1935, researchers found that after removing the frontal lobes of two chimps, they no longer experienced frustration or anxiety. Neurologist Egas Moniz believed that replicating this in humans could cure mental illness— leading to one of the most controversial and destructive medical treatments of the 20th century: the lobotomy. Jenell Johnson uncovers the history of the procedure. Lesson by Jenell Johnson, directed by Anton Bogaty.