抄録
Synchronous behavior such as dance has a power to create and sustain communities and communication in humans (McNeil, 1995). One distinctive characteristic of synchrony in humans from other animals is that it occurs within a pair. Experimental studies of synchrony are reporting that we humans tend to mutually couple a tempo of the movement with the partner. When might this mutual synchrony have emerged phylogenetically? To investigate whether non-human primates share this behavior, the current experiment targeted chimpanzees who are phylogenetically the closest living relatives to humans and one of highly social primate species. Four pairs of female chimpanzees in Kyoto University Primate Research Institute participated. Two conditions were prepared: alone and paired. A finger-tapping task was introduced to produce repetitive and rhythmic movement from the chimpanzees by using a push button. Mean of tapping intervals, time duration between beats, was calculated to examine whether tempo convergence between chimpanzees occurred when they simultaneously produced the tapping movement in the paired condition. Results from mean absolute difference of tapping intervals between chimpanzees depending on condition showed that tempo convergence occurred in all four pairs of chimpanzees. Further analysis from a difference of mean tapping intervals between conditions in each chimpanzee revealed that the tempo convergence occurred by unidirectional change. The current experiment demonstrated that humans and chimpanzees share to produce tempo convergence during simultaneous movement but the way how the convergence occurred seemed different between these two species.
