Abstract # 1065 Event # 37:

Scheduled for Thursday, August 18, 2005 04:30 PM-04:45 PM: Session 5 (Mayfair Room) Oral Presentation

Gesture-vocal synchrony in captive chimpanzees, Pan troglodytes

J. P. Taglialatela1 and W. D. Hopkins1,2
1Yerkes National Primate Research Center, Yerkes National Primate Research Center, Division of Psychobiology, 954 Gatewood Road, Atlanta, Georgia 30322, USA, 2Berry College
     A popular view of human language evolution proposes that speech may have evolved exclusively from a gestural system rather than communicative vocalizations. However, a number of recent studies propose that for at least captive chimpanzees and bonobos, vocalizations and gestures are employed concomitantly and differentially during intra- and interspecies communicative interactions. In addition, preferential use of the right hand, similar to that observed in humans, has been reported for chimpanzees during the production of gestures accompanied by vocalizations. This study sought to examine this concurrent use of manual gestures and vocalizations in 15 captive chimpanzees. Digital audio/video recordings of subjects gesturing towards an experimenter offering a food reward were collected. For each trial, the hand performing the gesture was noted, as were the presence or absence of a concurrent vocalization, and the relative temporal location of each action. The data indicated that the subjects paired their gestures with vocalizations significantly more often than expected by chance (χ2 = 29.03, P < 0.001). In addition, the latency between the onset of vocalization and the production of a right-handed or left-handed gesture was contingent upon the dominant hand (F1, 13 = 9.916, P < 0.01). The results suggest that the gesture and vocalization systems may be linked in the chimpanzee and support the claim that human language may have evolved from the concurrent evolution of manual and vocal communication.