“French university researchers measured the power of a smile by having two groups of subjects read the same comics page from the newspaper.  One group of subjects was instructed to hold a pencil in their teeth while reading (which activates the muscles used in smiling), while the other group held the pencil with their lips (which does not activate the muscles used in smiling).  Those who were unknowingly “smiling” found the cartoons far more humorous and had a better time while reading them than people in the group that weren’t smiling.”-Emotional Intelligence 2.0, Location 1102-1113