M. Haruno and C. D. Frith, “Activity in the Amygdala Elicited by Unfair Divisions Predicts Social Value Orientation,” Nat Nsci 13 (2010): 160; C. D. Batson, “Prosocial Motivation: Is It Ever Truly Altruistic?” Advances in Exp. Soc Psych 20 (1987): 65; A. G. Sanfey et al., “The Neural Basis of Economic Decision-Making in the Ultimatum Game,” Sci 300 (2003): 1755.
