Biology 103
2000 Third Web Report
On Serendip

For music to be an evolutionary behavior, it would have to be characteristic of all human cultures. Music is indeed universal; it exists in every culture. This is a small yet critical piece of evidence. The hypothesis that music has strong biological foundations requires universality; at the same time, universality is also compatible with a cultural commonality (1).

If music is a biological trait rather than a cultural development, it should be expressed in people before culture has influenced them, such as in infants. Preschoolers and infants do perceive and attend to musical stimuli. Research has shown that they do possess a musical ability remarkably similar to adults. Not only can they discriminate differences between similar notes, but they can also perceive and remember melodic contour using the adult strategy of listening to pitch relationships rather than the notes themselves, detect changes in rhythm, recognize a melody no matter at what tempo it is played, mentally divide sequences of sound into chunks or segments, and process consonance better than dissonance (1). All these things are done by adults when they process music. Preschool children also spontaneously break out into song during play, and are able to compose and perform their own fairly complex songs, not merely imitate adult songs(2). The hypothesis that music is a biological development is supported by the fact that infants and children show musical abilities before cultural factors can influence them.

Some other evidence that supports the hypothesis that music is a biological trait is that evidence suggests that it is old enough to be a product of evolution. The earliest found instrument is a bone flute discovered in Slovenia, which was dated between 43,000 and 82,000 years old; wooden flutes were undoubtedly used much earlier, and percussive instruments like drums and shakers earlier still. Singing must have predated instruments also, so music making has been in existence 50,000 to 250,000 years (3). Any adaptive behavior would have to be of sufficient antiquity for it to be a product of evolution; music definitely fulfills this requirement.

The existence of specialized areas of the brain used to process music is another piece of evidence supporting the biological development of music. Historically, it was believed that the right side of the brain was dominant in processing music while the left side of the brain processed language. Robert Zatorre has found that the right side of the brain is dominant in processing music. It has a greater density of nerves than the left side, allowing for a more detailed representation of sound frequencies; this is most likely an evolutionary structural development (4). However, there are specialized areas throughout the brain that process music: specific cells in the auditory cortex process pitch, melodic contour, and temporal aspects of music including rhythm. Research on patients who have suffered damage to the auditory cortex show even further divisions. For example, damage to the right hemisphere impairs the ability to process timbre, and the temporal processing is divided between rhythm processing in the left hemisphere and beat (meter) processing by the right hemisphere (1).

Any biological adaptation should have some sort of biochemical expression because evolution influences genes, which are expressed as proteins (3). Many studies have shown that music can influence and be modified by natural biochemical substances in the body. For example, when music elicits emotions, the physiological changes (such as blood circulation, respiration, skin conductivity and body temperature) can be measured (5). Also, music modulates the production of specific proteins in the body. One experiment showed that when music evokes pleasure, it causes the release of endorphins that stimulate the brain's opiate receptors, engaging the same physiological mechanisms employed by a variety of other pleasure-inducing behaviors. Another experiment found that testosterone levels dropped when the subjects listened to their favorite music as compared to a group that did not listen to music (3). As these two experiments show, music does cause a biochemical expression, giving more support to the hypothesis that music is an evolutionary adaptation.

Most arguments for music as being a purely cultural construction assert that music could not be an evolutionary trait because it has no survival value; it does not confer some advantage to human survival or procreation. However, evidence suggests that music could have indeed had some survival value in our developing culture.

One theory is that of sexual selection. In animals such as chimpanzees and songbirds, singing helps the animals attract mates; in the case of the chimps, a group of males singing together have a better chance of attracting mates than a single male singing alone (2). Music as a courting behavior would explain the human fascination with love songs and male singers' exerting physical attractiveness on females during concerts (6). However, sexual selection is usually found in cases of great sexual dimorphism, which humans do not exhibit, and does not explain the fact that women can (and do!) also sing (3).

Another theory is that music played a vital role in social bonding. It functioned in bonding both on an individual level, such as mothers and their infants, but also on a group level by fostering group identity and social cohesion, coordinating emotional states, and keeping people from arguing or fighting (4). Humans are not the only species that sing to strengthen bonds; male and female Siamang sing to establish and maintain pair-bonding (6). Singing may also have been a way for humans to occupy their spare time as they developed more sophisticated hunting methods. In nature, animals that are efficient in basic survival activities, like lions, seek to fill the rest of the time in innocuous ways, like sleeping (4). By spending time singing, humans would keep out of dangerous situations and behaviors.

There is a great deal of evidence to suggest that music may be an evolutionary adaptation rather than a cultural development: its universality, expression in infants, antiquity, specialized processing structures, biochemical expression, and role in social bonding. However, the existence of these things cannot prove that music is really an adaptation. It is just as likely that music is a cultural trait; however, evidence supporting this view is harder to find concrete evidence for. As Zatorre stated, "Not that [behavioral explanations] are wrong, but just that we don't have to postulate them. We can't ever prove them anyway" (4). The question of the origins of music is an extremely interesting one that can continue to be explored in order to make our understanding of the world and ourselves less wrong.

Personally, I would like to believe that music is an evolutionary development, part of the biology of every human being. This is because I feel that everyone has the ability to make music, vocal or instrumental, regardless of talent or skill. Music holds a special place in my life, and I believe that it must hold a place in everyone's life, for everyone is affected by music. I think that music truly can transcend barriers to the understanding and express things that we cannot consciously understand, but know on a deeper level of the subconscious. Humans are all music makers and dreamers of dreams.

WWW Sources

2) Evolution, Biology, and Music , short discussion and some evidence for biological/evolutionary theory

3) An Instinct for Music: Is Music an Evolutionary Adaptation?, detailed, objective argument and good evidence for evolutionary theory of music

4) The Biological Foundations of Music , discussion of evolutionary theory

5) The Biology of Music , presentation of research on how music is processed

6) The Musical Primate , argument for sexual selection

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