The facial-feedback hypothesis states that the contractions of the facial muscles may not only communicate what a person feels to others but also to the person himor herself. In other words, facial expressions are believed to have a direct influence on the experience of affect. This hypothesis goes back to Charles Darwin, who wrote that the expression of an emotion intensifies it, whereas its repression softens it. A second origin of the facial-feedback hypothesis is William James's theory of emotion, which states that the bodily changes follow the perception of an exciting fact and that the feeling of these bodily changes is the emotion. Although Darwin and James differ in their view of the role of the eliciting stimulus, they agree that the behavior that accompanies an emotion exerts a causal influence on its experience. In particular, the skeletal muscles were identified as important contributors. While Darwin has assigned the ...