This chapter describes how emotions arise and spread through the group. It is obvious that emotions can be induced in the members of a group if they are exposed to the same eliciting event at the same time. However, it is far less obvious how group processes intensify and maintain these emotions. The chapter discovers how research has explained the spread of emotion in a group. Emotional contagion can also occur because we automatically imitate the facial expressions, postures, and vocal expressions of others, particularly those who are part of our own group, and this imitation activates a similar emotion in ourselves. The chapter shows that specific emotions towards out-groups predict prejudice and even attitudes toward public policy. It examines how emotions toward groups motivate specific behavioral responses in addition to intentions. The chapter addresses the special situation in which members of different groups are in direct contact.