On Combat - The Psychology and hysiology of Deadly Conflict in War and in Peace by Lt. Col. Dave Grossman and Loren W. Christensen (third edition from 2007) is a well-written, evidence-based book about the reality of human behaviour in life-threatening situations. It is comprehensive (400 pages), provides detailed descriptions, (some) statistics as well as first-person recounts, historical context and other relevant information. But my main focus in this post is in the advice it gives and what lessons the LessWrong community may take from it.

TL;DR

In deadly force encounters you will experience and remember the most unusual physiological and psychological things. Innoculate yourself against extreme stress with repeated authentic training; play win-only paintball, train 911-dialing and -reporting. Train combat breathing. Talk to people after traumatic events.