This article develops a theory that explains how and when emotions, produced by social exchange, generate stronger or weaker ties to relations, groups, or networks. It is argued that social exchange produces positive or negative global feelings, which are internally rewarding or punishing. The theory indicates that social units (relations, groups, networks) are perceived as a source of these feelings, contingent on the degree of jointness in the exchange task. The jointness of the task is greatest if (1) actors find it difficult to distinguish their individual effects on or contributions to solving the exchange task (nonseparability) and (2) actors perceive a shared responsibility for success or failure at the exchange task. The theory explicates the effects of different exchange structures on these conditions and, in turn, on cohesion and solidarity. Implications are developed for network-to-group transformations. This article develops a theory that explains how and when emotions, produced by social exchange, generate stronger or weaker ties to relations, groups, or networks. It is argued that social exchange produces positive or negative global feelings, which are internally rewarding or punishing. The theory indicates that social units (relations, groups, networks) are perceived as a source of these feelings, contingent on the degree of jointness in the exchange task. The jointness of the task is greatest if (1) actors find it difficult to distinguish their individual effects on or contributions to solving the exchange task (nonseparability) and (2) actors perceive a shared responsibility for success or failure at the exchange task. The theory explicates the effects of different exchange structures on these conditions and, in turn, on cohesion and solidarity. Implications are developed for network-to-group transformations.This article proposes an affect theory of social exchange. The purpose is to incorporate emotions as an explicit, central feature of social exchange processes. The article accomplishes this by (1) conceptualizing individual actors as emoting as well as cognizing, feeling as well as thinking, (2) treating emotions as internal reinforcements or punishments, and (3) Social exchange is conceptualized as a joint activity of two or more actors in which each actor has something the other values. The implicit or explicit task in exchange is to generate benefit for each individual by exchanging behaviors or goods that actors cannot achieve alone (Thibaut and Kelley 1959;Homans 1961;Emerson 1972b). The affect theory of social exchange expands the domain of exchange theorizing in two main ways. First, exchange outcomes-rewards and punishments-are construed as having emotional effects that vary in form and intensity. When exchanges occur successfully, actors experience an emotional uplift (a "high"), and when exchanges do not occur successfully, they experience emotional "downs" (Lawler and Yoon 1996). Mild everyday feelings, therefore, are intertwined with exchange. Positive emotions include e...