We have all experienced it. As soon as there is music, we match our movements with the rhythms we hear. This phenomenon is so natural that we are right to wonder if our brain likes any musical rhythm. An American-German study, published in the journal Nature, looked into this phenomenon and shows that we have a preference for certain rhythms depending on our culture.
Researchers from MIT and the Max Planck Institute for Empirical Aesthetics came to this conclusion after conducting an experiment with 39 groups of participants from 15 countries, some of whom had already been studied in a previous study dating from 2017. A large number of volunteers come from cultures whose traditional music contains rhythmic patterns not found in Western music.
The academics played each group listen to a series of four randomly generated rhythms, before asking them to reproduce what they heard by clapping their hands. They then asked them to repeat the experiment but this time based on the rhythms they had produced themselves.
The scientists found that the musical sequences produced by the volunteers differed greatly from the original ones, suggesting that the latter were influenced by rhythmic biases. “The initial stimulus has a random structure, but with each iteration the structure is pushed by the listener’s biases, so that it tends to converge toward a particular point in the space of possible rhythms. This illustrates what we call anticipation, that is, the set of implicit internal expectations about rhythms that people have in mind“, explains Josh McDermott, associate professor of brain and cognitive sciences at MIT, in a press release.
Regional variations
Surprisingly, the research team found that participants’ rhythm biases varied, not from individual to individual, but based on their country of origin. So the American volunteers tended to produce rhythms with integer ratios like 1:1:2 and 2:3:3.
As a reminder, the notion of “integer ratios” indicates the duration relationships between different notes or beats. A 1:1:2 ratio refers to a sequence of three notes where the first and second are the same duration, while the third is twice as long as the two that preceded it. Similarly, the 2:3:3 ratio refers to a rhythmic sequence of three notes in which the last two notes are twice as long as the first.
Americans’ preference for 1:1:2 and 2:3:3 does not come from nowhere: these rhythmic sequences are very often used in Western music. Volunteers who belong to the Tsimané ethnic group in Bolivia produced different rhythms, probably closer to those of their traditional music.
But overall, study participants seemed to display a preference for musical sequences that follow a simple rhythmic structure. “Notre study provides the clearest evidence to date of a certain degree of universality in music perception and cognition, in that each group of participants tested exhibits a bias toward integer ratios. It also provides insight into the variation that can occur between crops and which can be very significant.“, says Nori Jacoby, lead author of this research, in the same press release.
Everything therefore suggests that music, and more particularly the notion of rhythm, transcends geographical boundaries, even if each culture has its own preferences when it comes to the fourth art.
Slide: The benefits of music on our brain
