DO you smile because you're happy, or are you happy because you are smiling? Darwin believed that facial expressions are indeed important for experiencing emotions. In The Expression of the Emotions in Man and Animals, he wrote that "the free expression by outward signs of an emotion intensifies it...[whereas]...the repression...of all outward signs softens our emotions." This idea was subsequently elaborated by the great psychologist William James, who suggested that "every representation of a movement awakens in some degree the actual movement which is its object."
Botox, which is used by millions of people every year to reduce wrinkles and frown lines on the forehead, works by paralyzing the muscles involved in producing facial expressions. A study due to be published in the journal Psychological Science suggests that by doing so, it impairs the ability to process the emotional content of language, and may diminish the quality of emotional experiences.