What Are Emotion Expressions For?

Although research on the nonverbal expression of emotion has played a prominent role throughout psychology during the past two decades—including an instrumental role in the development of contemporary evolutionary psychology—little research has focused on the evolutionary origins and functions of the emotional expressions themselves. However, recent findings from psychophysical, comparative, social, and cross-cultural psychology are converging to produce a compelling functionalist account, suggesting that emotional expressions serve critical adaptive purposes. Most of these studies have narrowly focused on single emotions—an approach that has been very useful for providing new insights about specific expressions but not for developing a broader understanding of why humans universally display and recognize distinct emotions. Here we unify these disparate findings in order to illuminate this fundamental form of social communication.