Facial and vocal expressions of emotion.

A flurry of theoretical and empirical work concerning the production of and response to facial and vocal expressions has occurred in the past decade. That emotional expressions express emotions is a tautology but may not be a fact. Debates have centered on universality, the nature of emotion, and the link between emotions and expressions. Modern evolutionary theory is informing more models, emphasizing that expressions are directed at a receiver, that the interests of sender and receiver can conflict, that there are many determinants of sending an expression in addition to emotion, that expressions influence the receiver in a variety of ways, and that the receiver's response is more than simply decoding a message.