Boosting cooperation between agents in diverse groups: a dynamical model of prosocial behavior, free-riding and coercive solutions.

Cooperation is usually stronger towards in-group members, because giving an upright signal about themselves implies higher possibilities of reciprocity among members with the same social identity. We examine the case where collaboration between two groups is a mandatory condition to achieve success in a particular project, but in the first one, the social identity is quite strong. We show that the existence of a small share of prosocial players in the first group can create a sort of "imitation effect" so that each new member puts more effort in cooperating with the outsiders. On the other side, to avoid free-riding effort should be conditional to the other's commitment. This way to boost cooperation is usually more efficient than a coercive strategy in the presence of significant sized majorities or feelings of resentments. Our analysis suggests that it is appropriate, under some circumstances, to stimulate a multicultural paradigm devoted to value and manage diversity through an acculturation process emphasizing adaptation, interdependence, and mutual appreciation of different cultures.