Amity-enmity complex

Amity-enmity complex is a term that was introduced by Arthur Keith in his work, A New Theory of Human Evolution (1948). The book posited that humans evolved as differing races, tribes, and cultures, exhibiting patriotism, morality, leadership, and nationalism. Those who belong are part of the in-group and are tolerated; all others are classed as out-group and are subject to hostility. "The code of enmity is a necessary part of the machinery of evolution. He who feels generous towards his enemy... has given up his place in the turmoil of evolutionary competition." Conscience in humans evolved a duality: to protect and save friends, and to hate and fight enemies. Keith's work summarized earlier opinions on human tribalism by Charles Darwin (The Descent of Man, 1879, chapter 7: On the Races of Man),  Alfred Russel Wallace (Darwinism, 1889, chapter 15), and Herbert Spencer.

Quotes

 * Monotheism rejects other Gods and the people who worship them. It is in the nature of monotheism to pick a quarrel... this exclusive spirit lies behind the specter of monotheist terrorism.
 * Michael Cook, A Brief History of the Human Race, Granta, 2005, p. 141.


 * Men like fighting and women like men who are prepared to fight on their behalf.
 * Jared Diamond, The Rise and Fall of the Third Chimpanzee, p. 287.