Abstract # 159:

Scheduled for Sunday, September 20, 2009 06:30 PM-09:00 PM: Session 14 (Mission Bay Ballroom CDE) Poster Presentation


D. A. Vasseur1, G. M. Grimshaw2, L. M. Marinus1, K. A. Short1 and N. G. Caine1
1CSU San Marcos, Department of Psychology, San Marcos, CA 92096, USA, 2School of Psychology, Victoria University of Wellington, PO Box 600, Wellington, New Zealand

There has been a great deal of interest in hand preference as a measure of laterality in nonhuman primates, in part because it may shed light on the origins of population level hand preference and language in humans. One important measure of hand preference is the consistency of any such preference over time. In this study we recorded naturally occurring hand preferences in a group of six bonobos (Pan paniscus) at the San Diego Zoo’s Wild Animal Park. The hand preferences of these bonobos had been assessed by another investigator (Shafer, 1997) eight years earlier. Pick and grasp were the behaviors of interest. We found that four of the bonobos retained a significant [z>1.96; two-tailed p<0.05] or nearly significant [z>1.75; p<0.08] right hand preference, one bonobo failed to show any hand preference at either time, and one showed a preference at the earlier but not the later time period. We also assessed four of our bonobos in a restricted tool use task and found strong hand preferences in all cases, but not necessarily in the same direction as the preferences they exhibited in the unrestricted pick and grasp behaviors. Based on this small sample, it appears that bonobo hand preference tends to be consistent over time, and those preferences may be dependent on postural demands or bimanual coordination.