A lENeE " In - Group Lov ~ ~ and " Out - Group Hate ~ ~ as Motiv for Individual P rticipation in Inter


What motivates individual be­ lmergroup conflicts? Is it the altruistic desire to l.n-£lrOUD or the drive to hurt the outthe gmne, tween these two motives. l'he game involves two groups. Each group member is given a monetary endowment and can decide how much ofit to contribute. Contribution can two one that "'''''''<l'U..' group at a personal cost and another in afUUtwn, ha.rms the out-group. An demonstrated that contributions in the IPD-MD game are made almost ex­ CHtSl:velv to the coopera preplay but not These results with those observed in the dilemma game, in which group members' con­ tributions are restricted to the communication increases human How can one and die for the which makes lethal war is it is often rational for Address School of Business Admin­ Je­ groups (e.g., natIOns, ethnic to it is rational for individual group members to in scale intere:rouD conflict. The effect one individual can structure creates a clear disincentive for individual group mem­ bers to In conAict. The for individual conflict must be to mobilize sufficient will not survive the aggres­ sion of other groups be able to exploit their and their members. conflict and alike, the benefits of costs of defeat. This is indeed human groups with more effective means of self-sacrifice in their members have over groups with less effective solidaritv mechanisms. thereby ol"Ooagating their Volume lSI-Number 4 2008 A~~o('iJtJon I)~)'chologi('al Scit'o('(" 405 In-Group Love and OUl-Group Hate : A New Game Paradigm altlUistic (i.e ., ethnocentric) norms and institutions (Bernhard , Fischbacher, & Fehr, 2006; Boyd, Gintis, Bowles, & Richerson, 2003) . MODELING INTERGROUP CONFLICT Int ergroup conflicts cannot be understood without taking into consideration the internal tension between group welfare and individual welfare. Because the relative success of the two groups in overcoming this intragroup conflict determines the outcome of the inte rgroup competition, the intragroup and in­ tergroup leve ls of conflict must be considered simultaneously. A bas ic mode l of this two-level structure is the intergroup prisoner's dilemma (IPD) game (Bornstein, 1992, 2003; Bornste in & Ben­ Yossef,1994). In this sec tion, we illustrate the IPD game using a specific set of parameters (see Bornstein , 2003, for a general definition) . The game is played by two groups, with 3 members in each group. Each player receives an endowment of 10 tokens and can con­ tribute any number of these tokens to the group's pool. For each token contributed by a me mber of the in-group, each of its members, including the contributor, gains 1 money unit (MU) and each me mber of the out-group loses 1 MU . For each token kept, the player is paid 2 M U. This simple game captures the key strategic properties of a large-scale intergroup conflict , as de­ scribed in the introduction. Because the individual's return from contributing a token is 1 MU, but his or her cost is 2 MU, the dominant individual strategy-the strategy that yields the highest personal payoffs regardless of what all the other in-group and out-group members dois to contribute nothing (i.e ., de­ fec t). However, because contributing a token generates a total of 3 MU for the group while costing only 2 MU, the dominant group strategy-the strategy that yields the highest payoffs for each group regardless of what the other group does-is for all group members to contribute a ll their tokens. These two properties define the intragroup payoff structure in the IPD game as an n-person (3-person in our example) pris­ oner's dilemma (PD) game (Dawes, 1980). This internal dilem­ ma, however, is embedded in a PD game between the two groups. If both groups execute the ir dominant strategies in this inter­ group game, both end up with relatively poor outcomes. From the collective point of view of both groups and all players, each token contlibuted is a ne t waste of2 MU, because the 2 MU that could be earned by keeping the token is traded off for an in­ group gain that is exactly offset by the out-group's loss. The collectively optimal strategy-the strategy that maximizes the payoff ofall players in both groups-is for all players to withhold contribution (i.e., defect). The relations among individual, group, and collective inter­ ests in inte rgroup conflicts as modeled by the IPD game are clearly illustrated by Dawes's (1980) battle example. Dawes observed that soldiers who fight in a large bailIe can reasonably conclude lhalno mailer whallheir comrades do they personaJly are beller off laking no chances; yet if no one takes chances, the result will be a rout and slaughter worse for all the soldiers than is taking chances. (p. 170) From the perspective of one side, the battle situation is a social dilemma with defection being rational for the individual but harmful to the group. However, from a broader perspective that includes all the soldiers on both sides, defection is both indi­ vidually rational and collectively efficient. All soldiers in the battle will be better off if they all act selfishly and take no chances, as then no one will be hurt. This additional level of superordinate or collective interest necessarily affects the motivational meaning of individual be­ havior. Whereas in a single-group dilemma, contributing is unmistakably altlUistic and defection is plainly selfish, in in­ tergroup conflicts as modeled by the IPD game, the motivation underlying individual behavior is inherently indistinct. Con­ tributing can be motivated by an altruistic desire to help the in­ group, but it can also result from an aggressive motivation to hurt the out-group (or the competitive motivation to increase the in­ group's advantage over the out-group). The motivation under­ lying defection is also ambiguous. Refusing to take part in war can reflect a tlUe altruistic concern for the collective welfare (of all players in both groups), but because defection is also con­ sistent with the individual's self-interest, a pacifist is always suspected of being a free rider. To disentangle these motivational ambiguities, we introduce a new paradigm, called the intergroup prisoner's dilemma-maxi­ mizing difference (IPD-MD) game. Like the IPD game, the IPD­ MD game involves a competition be tween two 3-member groups. Each group member receives an endowment of 10 tokens, each worth 2 MU, and can decide how many of these tokens to con­ tribute. Unlike in the IPD game, however, contributions can be made to two different pools . Contributing a token to the within­ group pool (pool W) increases the payoff for each in-group member, including the contributor, by 1 MU, without affecting the out-group. Contributing a token to the between-group pool (pool B) increases the payoff for each in-group member, in­ cluding the contributor, by 1 MU, and at the same time decreases the payoff for each out-group member by 1 MU . The choice between pools Wand B is what reveals the specific motivation underlying each individual's behavior. Contributing to pool W clearly indicates a cooperative motivation to benefit the in-group without hurting the out-group. Contributing to pool B, in contrast, indicates an aggressive motivation to hUlt the out­ group, or a competitive motivation to increase the in-group's advantage over the out-group.) As in the IPD game, a nalTowly I If players a re concerned only with th e ir in-group's welfare, and completely disregard tha t of the out-group, they should divid e the ir contributi on randomly between pools W a nd B. If, howe~er, players int e ntiona ll y restri ct th e ir con­ tributions to pool W, they must be attaching some po~itive va lue to the oul­ group's welfare, ra ther than being merel y indiffere nt to it. Volume 19-Number 4 406 Nir Halevy, Gary Bornstein, and Lilach Sagiv

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@inproceedings{Conflic2008AL, title={A lENeE " In - Group Lov ~ ~ and " Out - Group Hate ~ ~ as Motiv for Individual P rticipation in Inter}, author={oup Conflic and Lilach Sagiv}, year={2008} }