Why North America Is Not A Rhythm Nation

Music has a communal quality in virtually all cultures, inspiring dancing, clapping, instrument playing, marching, and chanting. Despite what seems to be a universal to coordinate movement, listeners are frequently challenged by the rhythmic patterns of other cultures. North American adults, for example, have difficulty perceiving rhythmic patterns in Balkan music.

Erin E. Hannon, Cornell University, and Sandra Trehub, University of Toronto, found that Bulgarian and Macedonian adults process complex musical rhythms better than North American adults, who often struggle with anything other than simple western meter. To gauge the significance of culture influences our ability to process musical patterns, the researchers also conducted experiments with North American infants and found that they too were better than North American adults.

It suggests that infants are capable of understanding complex rhythms but might lose that ability in a culture - like ours - that embraces a simple musical structure. The researchers also concluded that infants are more flexible than adults when it comes to categorizing different types of rhythms, but can lose this ability if they are exposed to only one type of rhythm when they are growing up. (Similar conclusions have been made about how people learn languages: Infants are more flexible in processing different word sounds and speech patterns from a variety of speakers, but it isn't long before they settle on those that are most common and meaningful to their culture.)

The new findings are reported in "Metrical Categories in Infancy and Adulthood" an article in the January 2005 issue of Psychological Science, a journal of the American Psychological Society.

"Our findings suggest that throughout our lives, as we passively experience ambient music (in the grocery store, in the car, in a restaurant) and as we actively listen to it (on our iPods), we actually shape and tune our perceptual processes in a manner that is specific to the music of our culture," Hannon said. "We showed that young infants, who have much less experience listening to music, lack these perceptual biases and thus respond to rhythmic structures that are both familiar and foreign. Although we know that young infants perceive speech in a manner that is language-general, our findings are unique and important in suggesting that the same is true for perception of musical rhythms."

In the experiments conducted by Hannon and Trehub, 50 North American college students and 17 first- or second-generation Bulgarian and Macedonian immigrants listened to four folkdance tunes from Serbia and Bulgaria. Two of the songs had a simple meter similar to western-style melodies (2 + 2 + 2 + 2) and two had a complex meter (2 + 2 + 3). The participants then listened to altered versions of the same four tunes, in which beats had been added to make the simple meters complex and the complex meters simple.

The North American participants were able to recognize when simple rhythms were changed to more complex ones, but they could not tell when the reverse happened. The Eastern European immigrants, however, were able to tell the difference between structure-changing and structure-preserving meters in all the tunes, whether or not their rhythms were simple or complex.

The experimenters then performed the same test on 64 six- and seven-month-old infants, observing whether they looked at or away from monitors showing the rhythmic sequences of the songs alternating between structure-changing and structure-preserving meters. The infants shared the Bulgarian and Macedonian immigrants' ability to distinguish the changes in both the simple and complex meters.

The experiments seemed to verify that humans are influenced by the rhythms in the music they are most accustomed to hearing, and that there aren't particular rhythms that are just naturally easier for the brain to process.

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Psychological Science is ranked among the top 10 general psychology journals for impact by the Institute for Scientific Information. The American Psychological Society represents psychologists advocating science-based research in the public's interest.