Quite a bold title. My understanding (while limited) is that the human ear senses sound by means of tiny hairs in the inner ear that vibrate in resonance with incoming sound waves. I've always believed that the reason certain intervals are more harmonious to us than others was because there would be some overlap in hairs that resonated for the different harmonious pitches. The same way guitar strings will resonate with other strings that are tuned an octave, or perfect fifth, or fourth higher, these ear-hairs ought to behave by the same physical laws and principles.

As such, I'm a bit skeptical of the method and conclusion of this research. It seems like physics to me, not psychology. Ability to reproduce pitches and intervals does not strike me as entirely related to what they were trying to find out.

How about instead playing different soundbites, of consonant and dissonant pitches, and asking for their opinion in some way? Maybe even allowing the participant to find a relationship by some sliding instrument themself? That would seem more aimed at studying the Tsimané's ability at "perceiving octaves."

Maybe my interpretation of the header and conclusion is wrong. Perhaps the idea is that _some training_ is needed in order to perceive octaves, the same way _some training_ is needed in order to learn how to walk. That I might be able to wrap my head around.