См., напр.: Masson, Jeffrey M., and S. McCarthy. When Elephants Weep: The Emotional Lives of Animals. — New York: Delacorte Press, 1995; Boehm, C. Hierarchy in the Forest: The Evolution of Egalitarian Behavior. — Cambridge, MA: Harvard University Press, 1999; Ridley, M. The Origins of Virtue: Human Instincts and the Evolution of Cooperation. — New York: Viking, 1997.
