Affect and emotions in intelligent agents: Why and how?

Starting with a strong distinction between affect and emotion, a characterization of an organism's effective functioning is presented in terms of the fit between an organism's functioning and the demands and opportunities that are presented by the environment in which it finds itself. It is proposed that effective functioning requires the interplay of four elements-affect, cognition, motivation, and behavior-and that the level of information processing (reactive, routine, or reflective) determines the manner in which the affect is differentiated. Two particular claims about emotion are then explored, namely, that typical full-blown emotions usually have all four elements present, and that emotions arise from the cognitive elaboration of undifferentiated affect. On this view, positive feelings about something deemed to be good, and negative feelings about something deemed to be bad are the bedrock of emotion, which, with the incorporation of cognition, break apart into conditions that look increasingly like emotions. Evidence of the value and utility of affect in humans is discussed, with three classic studies being summarized to demonstrate the consequences of positive and negative affect for attention and for judgment, as well as the effect of positive affect on altruistic behavior. Finally, problems associated with modeling the behavioral manifestations of emotions are discussed, with special attention to the potential ambiguity of facial expressions and emotion-relevant actions.