“…Drawing on social identity theory (Tajfel & Turner, 1979) and self-categorization theory (Turner, Hogg, Oakes, Reicher, & Wetherell, 1987), we argue that when group affiliations of helper and helpee are salient, helping interactions between individuals must be viewed as intergroup interactions (for similar arguments, see Levine & Crowther, 2008;Nadler, 2002). Because people derive an important part of their identity (i.e., their social identity) from their membership in social groups, group members are often concerned with the need to positively differentiate their group from other groups, that is, to stress their group's distinctiveness and portray their group as better than relevant comparison groups.…”