Starting shortly after birth and continuing throughout the life span, most individuals perceive and respond to the facial expressions of others during social interaction. Perception of facial expressions often involves drawing inferences about the feelings, attitudes, and emotions of the expresser. In addition to a constellation of facial and nonfacial cues, emotion inferences depend on situational context and other sources of relevant information about the expresser. Still, despite such ambiguities, children and adults are generally able to integrate various sources of information to make accurate inferences about other persons’ emotions. Perception of facial expression plays an important role in this process throughout the life span. Contemporary scholars of facial expressions tend to focus on the perception of emotions. This entry discusses foundational research on this ...