Facial Expressions 1 Running head: HUMOR, TICKLE, AND PAIN Facial Expressions, Smile Types, and Self-report during Humor, Tickle, and Pain: An Examination of Socrates’ Hypothesis Christine R. Harris Psychology Department University of California, San Diego Nancy Alvarado Center for Human Information Processing University of California, San Diego Author Contact: Christine R. Harris, Ph.D. Department of Psychology - 0109 University of California, San Diego La Jolla, CA 92093-0109 Phone: (858) 822-4507 Email:
[email protected] Word Count (main text and footnotes): 4028 Facial Expressions 2 Key words: emotion, facial expressions, laughter, humor, pain, tickling Facial Expressions 3 Abstract The nature of ticklish smiling and the possible emotional state that accompanies it have been pondered since the ancient Greeks. Socrates proposed that tickle induced pleasure and pain. Others, including Darwin, have claimed that ticklish laughter is virtually the same as humorous laughter. The present study is the first to systematically examine facial behavior and self-reports of emotion in response to tickling. Using a within-subjects design, 84 subjects’ responses to being tickled were compared to their responses when experiencing a painful stimulus and their responses to comedy. Overall results for both self-report and facial action coding showed that the tickle condition elicited both pleasure and displeasure. Facial action during tickling included “Duchenne” smiles plus movements associated with negative emotions. Results suggest that tickle-induced smiling can be dissociated from positive affect. Tickle may be a type of complex reflex or fixed-action pattern. Facial Expressions 4 Facial Expressions, Smile Types, and Self-report during Humor, Tickle, and Pain: An Examination of Socrates’ Hypothesis Tickling and the smiling it induces, at first blush, seem like child’s play.