“…In recent group dynamics studies, a new challenge has arisen regarding group identity from a multilevel perspective (Jans, Leach, Garcia, & Postmes, 2015; Leach et al, 2008; Ozeki & Yoshida, 2009, 2012; Postmes, Baray, Haslam, Morton, & Swaab, 2006; Swaab, Postmes, & Spears, 2008), about a quarter-century after Hogg (1992) proposed the basic idea of group-level group identity (GGI), in which he observed merely that a group whose members have a strong group identity is more cohesive. As yet, however, studies in social identity theory have failed to provide a full understanding of the concept of GGI.…”