31
Hedges, War is a Force, p. 3
32
I. Eibl-Eibesfeldt, Human Ethology (New York, 1989), p. 405
33
Lt. Col. Dave Grossman, On Killing: The Psychological Cost of Learning to Kill in War and Society, rev. ed. (New York, 2009), pp. 3–4
34
Joanna Bourke, An Intimate History of Killing: Face to Face Killing in Twentieth– Century Warfare (New York, 1999), p. 67
35
Peter Jay, Road to Riches or The Wealth of Man (London, 2000), pp. 35–36
36
K. J. Wenke, Patterns of Prehistory: Humankind’s First Three Million Years (New York, 1961), p. 130; John Keegan, A History of Warfare (London, 1993), pp. 120–21; O’Connell, Ride of Second Horseman, p. 35
