Lateralized scratching in chimpanzees (Pan troglodytes): Evidence of a functional asymmetry during arousal.
This study evaluated laterality in scratching by chimpanzees (n = 89) during socially arousing circumstances. Hand use and the side of the body scratched was recorded during a baseline and experimental condition. In the experimental condition, chimpanzees were shown a video of other conspecifics sharing, fighting over, and consuming a watermelon. Self-touches were categorized as either rubs or scratches. The chimpanzees showed a significant right hand bias for rubbing and also significantly directed the rubs to the right side of the body. For scratching, the chimpanzees showed no hand preference but a significant bias for scratching on the left side of the body. These results support the view that the right hemisphere regulates the autonomic nervous system during arousal.
Hopkins
William D
WD
Division of Psychobiology, Yerkes National Primate Research Center, Atlanta, GA 30322, USA. Lrcbh@rmy.emory.edu
Russell
Jamie L
JL
Freeman
Hani
H
Reynolds
Elizabeth A M
EA
Griffis
Caroline
C
Leavens
David A
DA
D000818:Animals; D001143:Arousal / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology; D001522:Behavior, Animal; D001921:Brain / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D008297:Male; D002679:Pan troglodytes; D010507:Periodicity; D011597:Psychomotor Performance / Q000502:physiology*; D012931:Social Environment; D014110:Touch; D014743:Videotape Recording