This chapter examines some of the literature demonstrating an impact of affect on social behavior. It will consider the influence of affect on cognition in an attempt to further understand on the way cognitive processes may mediate the effect of feelings on social behavior. The chapter describes the recent works suggesting an influence of positive affect on flexibility in cognitive organization (that is, in the perceived relatedness of ideas) and the implications of this effect for social interaction. The goal of this research is to expand the understanding of social behavior and the factors, such as affect, that influence interaction among people. Another has been to extend the knowledge of affect, both as one of these determinants of social behavior and in its own right. And a third has been to increase the understanding of cognitive processes, especially as they play a role in social interaction. Most recently, cognitive and social psychologists have investigated ways in which affective factors may participate in cognitive processes (not just interrupt them) and have begun to include affect as a factor in more comprehensive models of cognition. The research described in the chapter has focused primarily on feelings rather than intense emotion, because feelings are probably the most frequent affective experiences. The chapter focuses primarily on positive affect.