Does the Complexity of the Task Influence Manual Laterality in De Brazza’s Monkeys (Cercopithecus neglectus)?
Version of Record online: 17 SEP 2007
Volume 113, Issue 10, pages 983–994, October 2007
How to Cite
Schweitzer, C., Bec, P. and Blois-Heulin, C. (2007), Does the Complexity of the Task Influence Manual Laterality in De Brazza’s Monkeys (Cercopithecus neglectus)?. Ethology, 113: 983–994. doi: 10.1111/j.1439-0310.2007.01405.x
- Issue online: 17 SEP 2007
- Version of Record online: 17 SEP 2007
- Received: March 8, 2007 Initial acceptance: June 11, 2007 Final acceptance: June 11, 2007 (J. Kotiaho)
We assessed the manual preferences of 12 De Brazza’s monkeys (Cercopithecus neglectus) in spontaneous feeding situations and in two different coordinated bimanual tasks that were not visually guided. We recorded the hand used by each subject for 22 spontaneous activities, hand and digits use while extracting peanut butter from a hollow tube (tube task) and the hand used to extract candies from hanging plastic balls (ball task). Spontaneous activities revealed individual manual preferences but no population-level biases. For both experimental tasks, all subjects were lateralized in their hand use. We found a left bias at the group level for the tube task, but no group-level asymmetry for the ball task. Experimental tasks induced greater strength of laterality than did spontaneous activities. Although the size of our sample did not allow us to draw any conclusions concerning manual preference at the population level, this study stresses the importance of coordinated bimanual tasks to reveal manual laterality in non-human primates.