Abstract # 36:

Scheduled for Thursday, August 18, 2005 04:15 PM-04:30 PM: Session 5 (Mayfair Room) Oral Presentation

Hand-Use Preferences Among Pan Paniscus (Bonobos) at Wamba, Democratic Republic of Congo

E. J. Ingmanson
Bridgewater State College, Department of Anthropology, Tillinghast Hall 233, Bridgewater State College, Bridgewater, MA 02325, USA
     Examining hand-use preferences in the great apes can assist in understanding the evolutionary origins of the association between brain asymmetry and language, and its implications for tool-using behaviors. Data were collected from two communities of Pan Paniscus at Wamba, DRC. Four tasks were identified and hand-use preference recorded: 1) picking up an object, 2) branch dragging, a communicative activity, 3) peeling sugar cane, and 4) grooming. Individuals tended to be statistically consistent within a task, but not necessarily between tasks. The right hand was preferred by 95% of individuals from the E1 Group and 88% of E2 individuals for picking up an object. Branch dragging, however, was more often a left-handed activity, with 60% of individuals using this hand. The third and fourth tasks also showed statistically significant individual consistency. However, the two communities differed in prevalence of right verses left hand use. In the E1 Group, 65% of individuals preferred the right hand for the power grip task, while in E2 Group, 78% of individuals chose the left hand. Pan Paniscus appear more consistent in hand-use preferences at both the individual and group levels than reported for Pan troglodytes. These results emphasize the need to consider the nature of the task, individual differences, group differences, and the possible role that learning may have when evaluating hand-use preferences. Supported by Wenner-Gren Foundation, NSF, and Japan Society for the Promotion of Science.