Despite not having the ability to learn vocally, we have found, so far only two, specimens of macaques that know how to move to the rhythm of music.
One of the most distinctive characteristics of us humans is the ability to synchronize our movement with a constant rhythm: it requires being able to recognize patterns, predict how they will proceed and also considerable motor coordination. Beyond us humans, this ability is present only in some birds, and at an individual level in some primates.
In short, it is an ability that we still do not fully understand: until now, for example, we were convinced that moving to rhythm was intimately linked to vocal learning abilities. A new study published in Sciencehowever, denies this hypothesis: macaques also know how to dance, despite not having vocal abilities.
From the metronome… The theory that there was a close link between the ability to move in rhythm and that of learning new vocalizations was based on the hypothesis that rhythmic synchronization was a consequence of the presence of specialized brain circuits that control the interaction between hearing and movement; these circuits evolved to support vocal learning, and the connection is therefore easy to make. The first cracks in the theory came in recent years, when several studies demonstrated that macaques, which like almost all primates do not have the ability to vocal learningI am however able to follow a simple rhythm set by a metronome.
… To pop. The experiment of the Mexican team that conducted the study involved two macaques already trained to synchronize with a simple rhythm. The animals were subjected to a “qualitative leap”: instead of the ticking of a metronome, they were made to listen to songs – with an easy to identify rhythm, but still “enriched” with various melodies and arrangements. The macaques discovered that when they followed the rhythm, the humans rewarded them with food, and it took them a short time to synchronize with the songs.
Conditioned rhythm? Not only that: humans artificially increased or reduced the tempo of the songs, and the macaques adapted without problems. They did this even when they were played a song they didn’t know, and they continued even when the humans stopped rewarding them for getting in rhythm.
To be reevaluated in a natural context. The study. also warns against easy enthusiasm: for now we have only confirmed the complex rhythmic abilities of macaques in two specimens, and it took long and patient training to teach them to respond to music.
The fact that they were trained with food, then, indicates that they learned to pace themselves knowing that there was a reward, and as the authors explain in the study itself, «behavior that arises from conditioning may not be equivalent to behavior that emerges spontaneously».
Simply put, we first need to test macaques’ sense of rhythm in a natural setting to get the full picture.