Ingroup favoritism in cooperation in a dynamic intergroup context: Data from Israeli professional volleyball players

Abstract Past research has documented ingroup favoritism, the tendency to cooperate more with ingroup members than outgroup members, in a wide range of intergroup contexts, and extensively discussed conditions under which ingroup favoritism emerges. However, previous studies have predominantly focused on a simplistic intergroup context, for instance, where group boundaries are static, and one group membership is present. To fill the gap, we leveraged data from professional volleyball players and investigated the influence of (1) varying levels of intergroup conflict salience, (2) past and present group memberships, and (3) national team membership on intergroup cooperation. Contrary to our hypotheses and the social identity perspective, we found that conflict salience and former ingroup membership did not influence intergroup cooperation. Additionally, we found that the more national team players there are in the ingroup, the more cooperative those who play for the national team are with ingroup members, leading to increased ingroup favoritism.