Facial expressions can influence emotions

Research into the relationship between facial expressions and emotions has shown that controlling or preventing facial expressions dampens the experience of the associated emotions, even when other factors are the same. These findings have provided support to the facial feedback hypothesis, which was first articulated by Charles Darwin during his studies of human and animal emotions. Darwin wrote about the effect of facial expressions to either intensify or soften emotions during emotional experiences. Later, psychologist William James argued that facial expressions were a primary and independent physiological driver of emotions. The significance of facial feedback to emotions has been emphasized by studies of people with autism spectrum disorders, where difficulties in perceiving the emotions of others have been associated with difficulties in identifying facial expressions.