Music can make us tap our toes or help mend a broken heart. For centuries, people have instinctively taken advantage of its expressive and motivational powers, through dance, military marches, and modern-day workout mixes. But music is also laden with cultural meaning, history, and tradition. The fundamental link between movement and music has remained poorly understood, from a scientific point of view.
A team of Dartmouth College scientists embarked on an effort to strip music and movement down, to see if they could uncover a “shared structure” that would transcend cultural meaning and learned associations. They had a little bit of scientific work to build off of, suggesting the possible universal basis of the connection: baby researchers had found that even very young infants prefer music in a meter to which they had already been bounced. The way a runner slows down and stops, a group of researchers found, shares certain characteristics of the ends of musical pieces. And music is often written at speeds that aren’t far off from human beings’ most fundamental metronomes: heartbeats and walking speed.
To do their work, the Dartmouth researchers built a computer program that allowed participants to fuss with lots of different dimensions of movement or music: by tweaking settings, they could alter either a simple tune or an animated bouncing ball. The researchers then asked people to create the amalgam of settings that best expressed a variety of emotions. They looked to see if those settings were similar between music and movement—and then between cultures, by testing American college students and Cambodian villagers.
Thalia Wheatley, an assistant professor of psychology at Dartmouth, answered a few questions about the research, published in the Proceedings of the National Academy of Sciences in December.
Q: What did you find in this study, both in American college students and in Cambodian villagers?
A: We developed a computer program that allowed participants to generate emotional stimuli themselves by manipulating five slider bars that governed dynamic features of a bouncing ball: rate (speed of bounces), regularity of bounces, direction (up or down), size of bounces, and textural smoothness. Using this program, subjects created a different animated clip for each of five emotions: anger, happiness, fear, sadness, and peacefulness. Across our US participants, a specific and consistent dynamic signature for each emotion emerged. The most important feature of the program, however, was that each of the dynamic features were also mapped to musical features: rate (tempo), regularity of notes, pitch direction, size of pitch interval, and consonance. This cross-modal capability allowed us to test whether participants who used music to express an emotion set the sliders to the same positions as participants who expressed the same emotion with the moving ball.
The results were clear: each emotion was created with a particular configuration of dynamics (e.g., anger was fast, irregular and downward) and this configuration was the same in music and movement. We demonstrated the same findings in a remote Cambodian tribal village. This suggests that emotional expressions are crossmodal (the same in music and movement) and crosscultural.
Q: More broadly, what does something being “universal” mean? Does this mean the tie between music and movement is a universal one?
A: The reason why people get excited by claims of universality is the promise of finding something out about the human mind that is ancient and pervasive. Also, at least for me, it provides a sense of connection across cultures – that, deep down, we are more alike than we are different. ... Although our study demonstrated that the emotional expressions we tested are cross-cultural we are careful to point out that culture also plays a role. ... Also, I think it is important to keep in mind that we only tested 5 emotions: happy, sad, angry, peaceful and scared --it is not clear whether other emotions, emotion-blends and nuanced states like nostalgia have consistent, cross-cultural contours.
Q: A few years ago, a study found that parrots can entrain, or dance in time, to external beats. What does that suggest about how this connection evolved?
A: I remember when Snowball went viral. It is really interesting. ... Extracting a beat and coordinating movement in response is certainly an important part of the musical experience. Is it all of it? No. It is unclear, for example, whether these animals can keep track of nested patterns such as rhythms. Still, extracting a beat from sound and being able to resonate with that motorically may be an evolutionary precursor to music.
Q: How, specifically, can understanding the connection between movement and music help explain the origins of music or the evolution of human behavior?
A: Our data suggests that human dynamics are embedded in music. This allows us to resonate to music and to use music to engineer particular experiences. For example, we can use music to synchronize people within a group. We can also create music that makes people feel a certain way. We can put on a particular song and start to feel teenage angst or joy or melancholy, all on demand. This ability to engineer entrainment [synchronization] and emotion likely facilitated social communication and bonding and music allows us to do it on a very large scale (imagine the number of people at a U2 concert). This large scale coordination and cohesion allows us to create social networks that extend far beyond kinship. We think that even listening to music alone may be useful in that it tunes the brain to human dynamics which may then help us recognize social signals such as the emotion in someone’s voice.