Hardbound. Advances in Group Processes publishes theoretical analyses, reviews and theory based empirical chapters on group phenomena. Volume 19 includes papers that address fundamental issues of Solidarity, Cohesion and Trust . Chapter one shows how solidarity is a consequence of group-level phenomena (i.e. competition) and individual level phenomena (i.e. similarity). The second chapter examines solidarity among injection drug users, showing that the cohesion and solidarity of drug users are patterned by principles of collective action. The next two chapters integrate extant theories to provide new insights. Chapter three integrates principles of social exchange, status organizing processes, and game theory to theorize solidarity; while chapter four shows how new research on emotions can explain solidarity in status-differentiated groups. Two chapters then review and analyze long-standing programs of research on cohesion and trust. Chap
