Abstract # 2501 Poster # 69:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


DO CHIMPANZEES HAVE "SHIFTY EYES"? INVESTIGATING THE COOPERATIVE EYE HYPOTHESIS

K. Hall1, F. B. de Waal2 and R. W. Byrne1
1University of St Andrews, School of Psychology , St. Mary's College, St Andrews, Fife KY169JP, United Kingdom, 2Living Links Center, Yerkes National Primate Research Center, Emory University
line
     

The informed forager paradigm was used by Menzel [1974], Hare et al. [2000, 2001], and Hirata & Matsuzawa [2001] to show that chimpanzees are capable of tactical deception, and use the information of seeing and knowing to devise competitive strategies. In these studies, a dominant chimpanzee developed strategies to exploit a subordinate’s knowledge of hidden food, and the subordinate used tactics to mislead the dominant. An important question is whether the subordinate looks towards the food while leading the dominant elsewhere, giving the appearance of “shifty eyes.” Previous studies lack detail of the gaze interactions of the competitors; results show behavioral evidence of understanding mental states, but there is no discussion of the mechanism connecting what the subject observes and how she acts. A study that combines the controlled manipulations of Hare et al. [2000, 2001], while allowing the competition to take place in a larger arena to watch tactics develop, as in Hirata and Matsuzawa [2001], would elaborate how social knowledge is acquired and used. This study aimed to determine whether chimpanzees [Pan troglodytes] use concurrent visual information to modify competitive tactics, by charting their use of eye contact and gaze following by analyzing head orientation in relation to body movement. More generally, it establishes what attentional clues are available to reveal a chimpanzee’s real intentions, and whether a competitor can pick them up.