Free The World in Six Songs: How the Musical Brain Created Human Nature by Daniel J. Levitin

theorists might argue that these accounts are too recent (evolutionarily speaking) to be relevant to natural selection, for the good feelings that accompanied such exercises to have been shaped by natural selection. But where threats to life are concerned, natural selection can work its magic in just a few generations. Suppose there are some people who, by virtue of random mutation, enjoy eating dirt. An epidemic of a fatal virus sweeps the world, attacking hundreds of millions of people. It turns out that a particular compound, found only in dirt, kills the virus. Those people who eat dirt would survive and nearly everyone else could be wiped out within only one or two generations.
    What we call instinct in humans and animals is often nothing more than the product of natural selection at work. Consider house cats. Cats kick dirt or sand or whatever is nearby over their excrement. But it is unlikely that they understand the germ theory of disease and are covering their excrement to minimize contagion. Instead, some ancestral cats had a genetic mutation that triggered the release of certain reinforcing neurochemicals (let’s call them “happy juice”) when they kicked after excreting. The cats with this mutation were less likely to get sick or to spread disease to their offspring, facilitating this mutation’s rapid spread through the genome.
    By extension, humans who enjoyed singing, dancing, and marching together so much that they were drawn to it, attracted to it, and practiced it for thousands of hours were those who were the victors in any battles in which such drill conferred an advantage. The strong emotional, even neurochemical pleasure that resulted from synchronized movement may well have had a prehistoric antecedent. Our hunter-gatherer ancestors may have danced around the campfire before and after the hunt. By rehearsing their movements, they gained precision in their actions and were thus more likely to succeed. And taking down a large swift mammal with handheld tools likely required the coordinated movement of many accomplices. Modern army drill is probably an extension of this prehistoric behavior. Music traditionally has been characterized not only by sound but by action, and by interaction among makers of music-dance.
    Humans around the world report not just strong emotional bonding from synchronized, coordinated movement together, but feelings of a spiritual nature—a sense of there being a collective consciousness, the presence of a superior being, or an unseen world that is larger than what we immediately experience. The cognitive psychologist Jamshed Bharucha suggests an explanation for these feelings. The sense of group agency or collective consciousness that one feels when synchronized with others is more than an exhilarating feeling, he says. We feel this exhilaration, which comes from the neurochemical activity described above, and that leads the brain to seek a cause. Attribution—particularly causal attribution—is an automatic and compelling tendency of the brain. In fact, we can’t not attribute causes. As we sense a change in our emotional state, we look around to see what’s going on in the world that could explain our mood. In the case of group synchrony, we look around us and see all these other people dancing and singing with joy and excitement. In this way, the strange feeling (from the neurochemicals) becomes attributed to something beyond oneself. That’s why, in addition to the other advantages of group cohesion mentioned, religions make use of synchronization: It actually enhances the belief in a cause beyond oneself. So it’s more than just a good feeling; auditory and motor synchronization can lead to beliefs in forces that transcend the individual, such as societies.
    Music and coordinated movement were thus a way of creating meaningful social bonds for these four activities just reviewed: waging war, defending against attack, hunting prey, and forming work crews. A fifth and