This chapter summarizes emotions as social information (EASI) theory and provides a critical evaluation of its empirical support. I discuss how EASI relates to other theories on emotion, including the affect-as-information, affect infusion, and affect-as-input models. Next I discuss similarities and differences between EASI and models in the dual-process tradition. I also discuss the relationship between EASI and theorizing on emotional contagion, social appraisal, and reverse appraisal. Then I consider how EASI relates to affective events theory and the dual threshold model of anger. Next I highlight implications of the EASI framework for theory and research. Special attention is devoted to evolution and the social functionality of emotions, emotion regulation, emotional intelligence, the functional equivalence of expressive modalities, and the importance of studying discrete emotions rather than diffuse positive versus negative affect.