@booklet {nirhalevy-lahamfipiicangp2007,
	title = {Ingroup Love" and Outgroup Hate" as Motives for Individual Participation in Intergroup Conflict: A New Game Paradigm},
	howpublished = {Discussion Papers},
	year = {2007},
	month = {12},
	publisher = {Psychological Science (forthcoming)},
	abstract = {What motivates individual self-sacrificial behavior in intergroup conflicts? Is it the altruistic desire to help the ingroup or the aggressive drive to hurt the outgroup? This paper introduces a new game paradigm, the Intergroup Prisoner s Dilemma "Maximizing Difference (IPD-MD) game, designed specifically to distinguish between these two motives. The game involves two groups. Each group member is given a monetary endowment and can decide how much of it to contribute. Contribution can be made to either of two pools, one which benefits the ingroup at a personal cost, and another which, in addition, harms the outgroup. An experiment demonstrated that contributions in the IPD-MD game are made almost exclusively to the cooperative within-group pool. Moreover, pre-play intragroup communication increases intragroup cooperation but not intergroup competition. These results are compared with those observed in the Intergroup Prisoner{\textquoteright}s Dilemma (IPD) game, where group members{\textquoteright} contributions are restricted to the competitive between-group pool.},
	url = {/files/dp474.pdf},
	author = {Nir Halevy, Gary Bornstein and Lilach Sagiv}
}
