Affective phenomena permeate group life. When individuals work together in groups, feelings of pride, fear, hope, anger, and anxiety constantly emerge and have a profound influence on group member behavior. The experience and expression of moods and emotions shape whether group members form close bonds with one another, how they negotiate roles and status differences, resolve their conflicts, make decisions, and ultimately whether they accomplish their collective goals. After a long history of focusing on cognitive and behavioral processes, group researchers are beginning to take more...