Abstract # 2384 Event # 142:

Scheduled for Saturday, June 21, 2008 11:45 AM-11:55 AM: Session 15 (Meeting Room 2DEF) Oral Presentation

Contagious yawning in response to computer animations by chimpanzees

M. W. Campbell, J. D. Carter, D. Proctor and F. de Waal
Emory University, Living Links Center, Yerkes National Primate Research Center, 2409 Taylor Lane, Lawrenceville, GA 30043, USA
     In humans, contagious yawning has been associated with empathy, self-recognition, and theory-of-mind.  A small group (N=6) of chimpanzees (Pan troglodytes) has also displayed contagious yawning (Anderson et al., 2004).  We explored the possibility of using three-dimensional computer animations to stimulate contagious yawning on a larger population of chimpanzees.  Three unique virtual chimpanzees were animated to yawn, hoot, tooth-clack, and form play faces (all without sound).  The Yawn condition included repeated 10-second clips of the different yawn animations, and the Control condition included repeated 10-second clips of the other three expressions.  Each video lasted 15 minutes and consisted of 90 separate clips.  We tested 24 chimpanzees at the Yerkes National Primate Research Center in 12 mutually exclusive pairs.  Each pair saw each stimulus video twice, for a total of 4 sessions (one per day).  We observed the subjects during the video presentation and for 5 minutes after the video ended (in case of a build-up effect).  From video recordings we counted the number of yawns for each subject in each condition.  Some individuals made significantly more yawns in response to the Yawn video than the Control video [Binomial Sign Tests, a=0.05].  For an involuntary behavior to be stimulated, the chimpanzees must have identified with the animated chimpanzees to some extent.  Thus, computer-generated animations are potentially a flexible tool for studying emotion and cognition in chimpanzees.