A fascinating article in The Atlantic by David Eagleman. It begins with a recount of the murders committed by Charles Whitman at the University of Texas in 1966. Whitman left a suicide note asking that his brain be examined for abnormality and, in fact, a tumor was found. The note also said:
It was after much thought that I decided to kill my wife, Kathy, tonight … I love her dearly, and she has been as fine a wife to me as any man could ever hope to have. I cannot rationa[l]ly pinpoint any specific reason for doing this...Once you get past brain tumors pressuring specific areas of the brain that control aggression, fear, and impulse, it gets much more difficult.