Emotions also play a crucial role for guiding social behavior in most social species, including humans and primates. This chapter considers various theories of emotion, both historical and contemporary, and then places these theories into the context of the known neuroscientific basis of emotional processing. It shows that how the same brain networks are used to process both social stimuli as well as nonsocial stimuli with affective properties. The chapter also considers how social information is extracted from facial expressions and eye gaze. Evidence for the neural basis of theory of mind has come from several sources: functional imaging studies of neurotypical participants, studies of neurodevelopmental differences (primarily autism), and behavioral studies of patients with brain lesions.<\/p>\n\n\n\n