What is "killology"

n. The study of the psychological and physiological effects of killing and combat on the human psyche.

Killology is the study of the psychological and physiological effects of killing and combat on the human psyche; and the factors that enable and restrain killing in these situations.

The term and field of study was invented by Lt. Col. Dave Grossman (US Army, Ret.) of the Killology Research Group in his 1995 book On Killing: The Psychological Cost of Learning to Kill in War and Society.