Reply to Bertolo et al.: Rhythmic swaying in chimpanzees has implications for understanding the biological roots of music and dance.

Bertolo et al. claim that reported rhythmic swaying in chimpanzees (1) is caused by a nonmusical mechanism (2). However, the swaying reported in ref. 1 differs from distress responses to aversive stimuli, and may elucidate the biological roots of human music and dance. First, Bertolo et al.’s (2) concern about interindividual heterogeneity is not relevant; previous studies have reported sex differences in chimpanzees’ responsiveness to sound [e.g., rain dance (3)]. The large difference between our most and least active chimpanzees is consistent with this well-known variability. Even so, all of our chimpanzees showed rhythmic movement … [↵][1]1To whom correspondence may be addressed. Email: yuko.hattori{at}gmail.com. [1]: #xref-corresp-1-1