[Excerpt] This chapter poses the question: How do emotional aspects of social interaction affect the emergence and salience of collective identities? I assume that social interaction inherently involves an implicit or explicit joint task—namely to accomplish some result that can only be produced with others. The most fundamental “task” of social interaction can be construed as the coordination and alignment of behavior, such that actors successfully conclude the interact ion episode. Essential to this task is a working consensus about definitions of self and other in the social situation, i.e., consensual self-other identities. A central component of my argument is that social interaction has emotional effects that vary with the success of actors at accomplishing this fundamental task. This paper theorizes the conditions under which emotional effects of social interaction promote collective identities that bridge or transcend self-other role identities.