[Excerpt] Emotions are likely to be produced when two or more people exchange valued outcomes (i.e., goods, rewards, payoffs). Emotions are internal events that occur within an actor and that stem from conditions or events external to the actor (e.g., the behavior of others, results of exchange, social context). These may take various forms, including general feelings of pleasure/satisfaction or displeasure/dissatisfaction or more specific feelings of anger, shame, pride, gratitude, and so forth. It is reasonable to presume that any emotions felt by actors due to their exchange could have important effects on their future exchanges and their relationships. For example, if the exchanges make them feel good or feel gratitude toward each other, their inclination to exchange should increase and they may develop a stronger relationship over time. On the other hand, if they feel anger or shame after concluding an exchange, their inclination to exchange in the future should decrease and a relationship may not develop at all. This chapter reviews theoretical and empirical work bearing on how and when emotions or feelings from social exchange affect the development and strength of social relations and groups.