http://www.sciencedaily.com/releases/20 … 103923.htm

"Psychologists ... conducted two experiments to see if emotion language has an influence on facial muscle activity. In the first experiment, a group of students read a series of emotion verbs (e.g., "to smile," "to cry") and adjectives (e.g., "funny," "frustrating") on a monitor, while the activity of their zygomatic major (the muscle responsible for smiles) and corrugator supercilii (which causes frowns) muscles were measured.

The results showed that reading action verbs activated the corresponding muscles. For example, "to laugh" resulted in activation of the zygomatic major muscle, but did not cause any response in the muscles responsible for frowning."