People’s attitudes are at the center of social relations and to the heart of the dynamics of social processes. Attitudes are rarely idiosyncratic, but more often they are grounded in the groups we belong to. During the last two decades, research on intergroup attitudes has been enriched by indirect measures assessing spontaneous (implicit) attitudes that are distinguished from controlled (explicit) ones. Whereas explicit attitudes can form and change quickly, implicit attitudes are assumed to stem from long-term experiences and to be resistant to change (Greenwald & Banaji, 1995; Wilson, Lindsey, & Schooler, 2000). However, there is accumulating evidence that implicit attitudes in general and towards social groups in particular can form quickly based on descriptive information (Gregg, Seibt, & Banaji, 2006) or mere group membership (e.g., Otten & Moskowitz, 2000). Concerning the malleability of attitudes towards social groups, empirical evidence is diverse (see Blair, 2002 for the malleability of implicit attitudes; and Gregg et al., for their stability). Recent theorizing takes the diverse findings on the relative malleability of implicit and explicit attitudes into account and addresses their underlying processes and operating systems (e.g., Gawronski & Bodenhausen, 2006; Petty, Brinol, & DeMarree, 2007). It is still an ongoing debate why and when attitudes generally form and change (Gawronski & Sritharan, 2010). Specifically little attention has been paid to the influence of group membership on forming and changing intergroup attitudes.