Mizuho Shinada

The private rejection of unfair offers and emotional commitment

In a series of experiments, we demonstrate that certain players of an economic game reject unfair offers even when this behavior increases rather than decreases inequity. A substantial proportion (30–40%, compared with 60–70% in the standard ultimatum game) of those who responded rejected unfair offers even when rejection reduced only their own earnings to 0, while not affecting the earnings of the person who proposed the unfair split (in an impunity game). Furthermore, even when the responders were not able to communicate their anger to the proposers by rejecting unfair offers in a private impunity game, a similar rate of rejection was observed. The rejection of unfair offers that increases inequity cannot be explained by the social preference for inequity aversion or reciprocity; however, it does provide support for the model of emotion as a commitment device. In this view, emotions such as anger or moral disgust lead people to disregard the immediate consequences of their behavior, committing them to behave consistently to preserve integrity and maintain a reputation over time as someone who is reliably committed to this behavior.

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner’s dilemma game. We did not find any correlation between the participants’ tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants’ responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status.

Bringing Back Leviathan into Social Dilemmas

More than three and a half centuries ago, the great ancestor of the contemporary social dilemma researchers, Thomas Hobbes, published the most influential book on social dilemmas ever (Hobbes, 1651) and argued that social order cannot be maintained without authority that controls individuals’ unrestricted pursuit of selfinterest. According to Hobbes, people who prefer peace (mutual cooperation) to a war of all against all (mutual defection) should agree to give birth to Leviathan, or a government or authority that enforces social order. In “the tragedy of commons,” Garrett Hardin (1968) talks about the modern version of the Hobbesian problem of social order. In this influential article, Hardin uses a parable of English commons to illustrate how and why communities fail to maintain their resources. Consider the pasture that is open to all herdsmen in a village. Suppose there is no rule for regulating the use of the pasture or social institutions that enforce such rules. Each herdsman can freely add his sheep on the common pasture. The increase in the demand for wool in fact induced English villagers to add more sheep than the pasture could sustain. This “rational” behavior of each herdsman produced depletion of grasses on the commons. This familiar parable drew the attention of the general public in the 1970s when people became aware of resource problems on a global scale. Hardin’s (1968) recommendation for the prevention of the “tragedy” echoes that of Hobbes’; he recommended that coercion—“coercion, mutually agreed upon by the majority of the people affected” (Hardin, 1968, p. 1247)— not conscience, provides a solution to the tragedy. He even stated that “a call for voluntary compliance would be counterproductive” (Hardin, 1977, p. 129). Hardin’s recommendation for coercion as the solution to the social dilemma problem created much controversy in various fields, inviting criticism because of its brutal Hobbesian appearance (Crowe, 1969; Fox, 1985; Lynn & Oldenquist, 1986; Stillman, 1975; Taylor, 1976, 1982). Subsequent studies of social dilemmas in psychology mostly ignored the recommendation—mutual coercion mutually agreed upon—by the two giants of social dilemma research, and mostly focused on how and among whom “voluntary compliance” emerges (for reviews of psychological studies of social dilemmas, see Dawes, 1980; Kollock, 1998; Messick & Brewer, 1983; Stroebe &