For example, Kahneman et al. (1986) present evidence indicating that individuals willingly sacrificed money to punish an act of intended unfairness (and to reward a prior act of intended fairness). In a series of four experimental studies, Turillo, Folger, Lavelle,Umphress, and Gee (2002) extended these ideas. Their first three studies indicated that participants were willing to sacrifice their financial self-interest in reaction to unfairness, even when there were no material or symbolic benefits (e.g., reputation-related) for doing this. Taken together, these studies ruled out the possibility of monetary payoffs (because participants had to pay to punish the wrong-doer), deterrence (because the transgressor did not know he or she was being punished), and group affiliation (because they did not know either the perpetrator or victim). Based on these considerations,Kahneman et al. and Turillo et al. maintained that individuals are motivated to act based upon an internalized sense of duty to uphold moral norms.